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<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>E.253. Release 8.1</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="prev" href="release-8-1-1.html" title="E.252. Release 8.1.1" /><link rel="next" href="release-8-0-26.html" title="E.254. Release 8.0.26" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">E.253. Release 8.1</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="release-8-1-1.html" title="E.252. Release 8.1.1">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="release.html" title="Appendix E. Release Notes">Up</a></td><th width="60%" align="center">Appendix E. Release Notes</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.1 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="release-8-0-26.html" title="E.254. Release 8.0.26">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="RELEASE-8-1"><div class="titlepage"><div><div><h2 class="title" style="clear: both">E.253. Release 8.1</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="release-8-1.html#id-1.11.6.257.3">E.253.1. Overview</a></span></dt><dt><span class="sect2"><a href="release-8-1.html#id-1.11.6.257.4">E.253.2. Migration to Version 8.1</a></span></dt><dt><span class="sect2"><a href="release-8-1.html#id-1.11.6.257.5">E.253.3. Additional Changes</a></span></dt></dl></div><p><strong>Release date: </strong>2005-11-08</p><div class="sect2" id="id-1.11.6.257.3"><div class="titlepage"><div><div><h3 class="title">E.253.1. Overview</h3></div></div></div><p> Major changes in this release: </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> Improve concurrent access to the shared buffer cache (Tom) </span></dt><dd><p> Access to the shared buffer cache was identified as a significant scalability problem, particularly on multi-CPU systems. In this release, the way that locking is done in the buffer manager has been overhauled to reduce lock contention and improve scalability. The buffer manager has also been changed to use a <span class="quote">“<span class="quote">clock sweep</span>”</span> replacement policy. </p></dd><dt><span class="term"> Allow index scans to use an intermediate in-memory bitmap (Tom) </span></dt><dd><p> In previous releases, only a single index could be used to do lookups on a table. With this feature, if a query has <code class="command">WHERE tab.col1 = 4 and tab.col2 = 9</code>, and there is no multicolumn index on <code class="literal">col1</code> and <code class="literal">col2</code>, but there is an index on <code class="literal">col1</code> and another on <code class="literal">col2</code>, it is possible to search both indexes and combine the results in memory, then do heap fetches for only the rows matching both the <code class="literal">col1</code> and <code class="literal">col2</code> restrictions. This is very useful in environments that have a lot of unstructured queries where it is impossible to create indexes that match all possible access conditions. Bitmap scans are useful even with a single index, as they reduce the amount of random access needed; a bitmap index scan is efficient for retrieving fairly large fractions of the complete table, whereas plain index scans are not. </p></dd><dt><span class="term"> Add two-phase commit (Heikki Linnakangas, Alvaro, Tom) </span></dt><dd><p> Two-phase commit allows transactions to be "prepared" on several computers, and once all computers have successfully prepared their transactions (none failed), all transactions can be committed. Even if a machine crashes after a prepare, the prepared transaction can be committed after the machine is restarted. New syntax includes <code class="command">PREPARE TRANSACTION</code> and <code class="command">COMMIT/ROLLBACK PREPARED</code>. A new system view <code class="literal">pg_prepared_xacts</code> has also been added. </p></dd><dt><span class="term"> Create a new role system that replaces users and groups (Stephen Frost) </span></dt><dd><p> Roles are a combination of users and groups. Like users, they can have login capability, and like groups, a role can have other roles as members. Roles basically remove the distinction between users and groups. For example, a role can: </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Have login capability (optionally) </p></li><li class="listitem"><p> Own objects </p></li><li class="listitem"><p> Hold access permissions for database objects </p></li><li class="listitem"><p> Inherit permissions from other roles it is a member of </p></li></ul></div><p> Once a user logs into a role, she obtains capabilities of the login role plus any inherited roles, and can use <code class="command">SET ROLE</code> to switch to other roles she is a member of. This feature is a generalization of the SQL standard's concept of roles. This change also replaces <code class="structname">pg_shadow</code> and <code class="structname">pg_group</code> by new role-capable catalogs <code class="structname">pg_authid</code> and <code class="structname">pg_auth_members</code>. The old tables are redefined as read-only views on the new role tables. </p></dd><dt><span class="term"> Automatically use indexes for <code class="function">MIN()</code> and <code class="function">MAX()</code> (Tom) </span></dt><dd><p> In previous releases, the only way to use an index for <code class="function">MIN()</code> or <code class="function">MAX()</code> was to rewrite the query as <code class="command">SELECT col FROM tab ORDER BY col LIMIT 1</code>. Index usage now happens automatically. </p></dd><dt><span class="term"> Move <code class="filename">/contrib/pg_autovacuum</code> into the main server (Alvaro) </span></dt><dd><p> Integrating autovacuum into the server allows it to be automatically started and stopped in sync with the database server, and allows autovacuum to be configured from <code class="filename">postgresql.conf</code>. </p></dd><dt><span class="term"> Add shared row level locks using <code class="command">SELECT ... FOR SHARE</code> (Alvaro) </span></dt><dd><p> While <span class="productname">PostgreSQL</span>'s MVCC locking allows <code class="command">SELECT</code> to never be blocked by writers and therefore does not need shared row locks for typical operations, shared locks are useful for applications that require shared row locking. In particular this reduces the locking requirements imposed by referential integrity checks. </p></dd><dt><span class="term"> Add dependencies on shared objects, specifically roles (Alvaro) </span></dt><dd><p> This extension of the dependency mechanism prevents roles from being dropped while there are still database objects they own. Formerly it was possible to accidentally <span class="quote">“<span class="quote">orphan</span>”</span> objects by deleting their owner. While this could be recovered from, it was messy and unpleasant. </p></dd><dt><span class="term"> Improve performance for partitioned tables (Simon) </span></dt><dd><p> The new <code class="varname">constraint_exclusion</code> configuration parameter avoids lookups on child tables where constraints indicate that no matching rows exist in the child table. </p><p> This allows for a basic type of table partitioning. If child tables store separate key ranges and this is enforced using appropriate <code class="command">CHECK</code> constraints, the optimizer will skip child table accesses when the constraint guarantees no matching rows exist in the child table. </p></dd></dl></div></div><div class="sect2" id="id-1.11.6.257.4"><div class="titlepage"><div><div><h3 class="title">E.253.2. Migration to Version 8.1</h3></div></div></div><p> A dump/restore using <span class="application">pg_dump</span> is required for those wishing to migrate data from any previous release. </p><p> The 8.0 release announced that the <code class="function">to_char()</code> function for intervals would be removed in 8.1. However, since no better API has been suggested, <code class="function">to_char(interval)</code> has been enhanced in 8.1 and will remain in the server. </p><p> Observe the following incompatibilities: </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> <code class="varname">add_missing_from</code> is now false by default (Neil) </p><p> By default, we now generate an error if a table is used in a query without a <code class="literal">FROM</code> reference. The old behavior is still available, but the parameter must be set to 'true' to obtain it. </p><p> It might be necessary to set <code class="varname">add_missing_from</code> to true in order to load an existing dump file, if the dump contains any views or rules created using the implicit-<code class="literal">FROM</code> syntax. This should be a one-time annoyance, because <span class="productname">PostgreSQL</span> 8.1 will convert such views and rules to standard explicit-<code class="literal">FROM</code> syntax. Subsequent dumps will therefore not have the problem. </p></li><li class="listitem"><p> Cause input of a zero-length string (<code class="literal">''</code>) for <code class="type">float4</code>/<code class="type">float8</code>/<code class="type">oid</code> to throw an error, rather than treating it as a zero (Neil) </p><p> This change is consistent with the current handling of zero-length strings for integers. The schedule for this change was announced in 8.0. </p></li><li class="listitem"><p> <code class="varname">default_with_oids</code> is now false by default (Neil) </p><p> With this option set to false, user-created tables no longer have an OID column unless <code class="command">WITH OIDS</code> is specified in <code class="command">CREATE TABLE</code>. Though OIDs have existed in all releases of <span class="productname">PostgreSQL</span>, their use is limited because they are only four bytes long and the counter is shared across all installed databases. The preferred way of uniquely identifying rows is via sequences and the <code class="type">SERIAL</code> type, which have been supported since <span class="productname">PostgreSQL</span> 6.4. </p></li><li class="listitem"><p> Add <code class="literal">E''</code> syntax so eventually ordinary strings can treat backslashes literally (Bruce) </p><p> Currently <span class="productname">PostgreSQL</span> processes a backslash in a string literal as introducing a special escape sequence, e.g. <code class="literal">\n</code> or <code class="literal">\010</code>. While this allows easy entry of special values, it is nonstandard and makes porting of applications from other databases more difficult. For this reason, the <span class="productname">PostgreSQL</span> project is planning to remove the special meaning of backslashes in strings. For backward compatibility and for users who want special backslash processing, a new string syntax has been created. This new string syntax is formed by writing an <code class="literal">E</code> immediately preceding the single quote that starts the string, e.g. <code class="literal">E'hi\n'</code>. While this release does not change the handling of backslashes in strings, it does add new configuration parameters to help users migrate applications for future releases: </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p> <code class="varname">standard_conforming_strings</code> — does this release treat backslashes literally in ordinary strings? </p></li><li class="listitem"><p> <code class="varname">escape_string_warning</code> — warn about backslashes in ordinary (non-E) strings </p></li></ul></div><p> The <code class="varname">standard_conforming_strings</code> value is read-only. Applications can retrieve the value to know how backslashes are processed. (Presence of the parameter can also be taken as an indication that <code class="literal">E''</code> string syntax is supported.) In a future release, <code class="varname">standard_conforming_strings</code> will be true, meaning backslashes will be treated literally in non-E strings. To prepare for this change, use <code class="literal">E''</code> strings in places that need special backslash processing, and turn on <code class="varname">escape_string_warning</code> to find additional strings that need to be converted to use <code class="literal">E''</code>. Also, use two single-quotes (<code class="literal">''</code>) to embed a literal single-quote in a string, rather than the <span class="productname">PostgreSQL</span>-supported syntax of backslash single-quote (<code class="literal">\'</code>). The former is standards-conforming and does not require the use of the <code class="literal">E''</code> string syntax. You can also use the <code class="literal">$$</code> string syntax, which does not treat backslashes specially. </p></li><li class="listitem"><p> Make <code class="command">REINDEX DATABASE</code> reindex all indexes in the database (Tom) </p><p> Formerly, <code class="command">REINDEX DATABASE</code> reindexed only system tables. This new behavior seems more intuitive. A new command <code class="command">REINDEX SYSTEM</code> provides the old functionality of reindexing just the system tables. </p></li><li class="listitem"><p> Read-only large object descriptors now obey MVCC snapshot semantics </p><p> When a large object is opened with <code class="literal">INV_READ</code> (and not <code class="literal">INV_WRITE</code>), the data read from the descriptor will now reflect a <span class="quote">“<span class="quote">snapshot</span>”</span> of the large object's state at the time of the transaction snapshot in use by the query that called <code class="function">lo_open()</code>. To obtain the old behavior of always returning the latest committed data, include <code class="literal">INV_WRITE</code> in the mode flags for <code class="function">lo_open()</code>. </p></li><li class="listitem"><p> Add proper dependencies for arguments of sequence functions (Tom) </p><p> In previous releases, sequence names passed to <code class="function">nextval()</code>, <code class="function">currval()</code>, and <code class="function">setval()</code> were stored as simple text strings, meaning that renaming or dropping a sequence used in a <code class="literal">DEFAULT</code> clause made the clause invalid. This release stores all newly-created sequence function arguments as internal OIDs, allowing them to track sequence renaming, and adding dependency information that prevents improper sequence removal. It also makes such <code class="literal">DEFAULT</code> clauses immune to schema renaming and search path changes. </p><p> Some applications might rely on the old behavior of run-time lookup for sequence names. This can still be done by explicitly casting the argument to <code class="type">text</code>, for example <code class="literal">nextval('myseq'::text)</code>. </p><p> Pre-8.1 database dumps loaded into 8.1 will use the old text-based representation and therefore will not have the features of OID-stored arguments. However, it is possible to update a database containing text-based <code class="literal">DEFAULT</code> clauses. First, save this query into a file, such as <code class="filename">fixseq.sql</code>: </p><pre class="programlisting"> SELECT 'ALTER TABLE ' || pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname) || ' ALTER COLUMN ' || pg_catalog.quote_ident(a.attname) || ' SET DEFAULT ' || regexp_replace(d.adsrc, $$val\(\(('[^']*')::text\)::regclass$$, $$val(\1$$, 'g') || ';' FROM pg_namespace n, pg_class c, pg_attribute a, pg_attrdef d WHERE n.oid = c.relnamespace AND c.oid = a.attrelid AND a.attrelid = d.adrelid AND a.attnum = d.adnum AND d.adsrc ~ $$val\(\('[^']*'::text\)::regclass$$; </pre><p> Next, run the query against a database to find what adjustments are required, like this for database <code class="literal">db1</code>: </p><pre class="programlisting"> psql -t -f fixseq.sql db1 </pre><p> This will show the <code class="command">ALTER TABLE</code> commands needed to convert the database to the newer OID-based representation. If the commands look reasonable, run this to update the database: </p><pre class="programlisting"> psql -t -f fixseq.sql db1 | psql -e db1 </pre><p> This process must be repeated in each database to be updated. </p></li><li class="listitem"><p> In <span class="application">psql</span>, treat unquoted <code class="literal">\{digit}+</code> sequences as octal (Bruce) </p><p> In previous releases, <code class="literal">\{digit}+</code> sequences were treated as decimal, and only <code class="literal">\0{digit}+</code> were treated as octal. This change was made for consistency. </p></li><li class="listitem"><p> Remove grammar productions for prefix and postfix <code class="literal">%</code> and <code class="literal">^</code> operators (Tom) </p><p> These have never been documented and complicated the use of the modulus operator (<code class="literal">%</code>) with negative numbers. </p></li><li class="listitem"><p> Make <code class="literal">&<</code> and <code class="literal">&></code> for polygons consistent with the box "over" operators (Tom) </p></li><li class="listitem"><p> <code class="command">CREATE LANGUAGE</code> can ignore the provided arguments in favor of information from <code class="structname">pg_pltemplate</code> (Tom) </p><p> A new system catalog <code class="structname">pg_pltemplate</code> has been defined to carry information about the preferred definitions of procedural languages (such as whether they have validator functions). When an entry exists in this catalog for the language being created, <code class="command">CREATE LANGUAGE</code> will ignore all its parameters except the language name and instead use the catalog information. This measure was taken because of increasing problems with obsolete language definitions being loaded by old dump files. As of 8.1, <span class="application">pg_dump</span> will dump procedural language definitions as just <code class="command">CREATE LANGUAGE <em class="replaceable"><code>name</code></em></code>, relying on a template entry to exist at load time. We expect this will be a more future-proof representation. </p></li><li class="listitem"><p> Make <code class="function">pg_cancel_backend(int)</code> return a <code class="type">boolean</code> rather than an <code class="type">integer</code> (Neil) </p></li><li class="listitem"><p> Some users are having problems loading UTF-8 data into 8.1.X. This is because previous versions allowed invalid UTF-8 byte sequences to be entered into the database, and this release properly accepts only valid UTF-8 sequences. One way to correct a dumpfile is to run the command <code class="command">iconv -c -f UTF-8 -t UTF-8 -o cleanfile.sql dumpfile.sql</code>. The <code class="literal">-c</code> option removes invalid character sequences. A diff of the two files will show the sequences that are invalid. <code class="command">iconv</code> reads the entire input file into memory so it might be necessary to use <span class="application">split</span> to break up the dump into multiple smaller files for processing. </p></li></ul></div></div><div class="sect2" id="id-1.11.6.257.5"><div class="titlepage"><div><div><h3 class="title">E.253.3. Additional Changes</h3></div></div></div><p> Below you will find a detailed account of the additional changes between <span class="productname">PostgreSQL</span> 8.1 and the previous major release. </p><div class="sect3" id="id-1.11.6.257.5.3"><div class="titlepage"><div><div><h4 class="title">E.253.3.1. Performance Improvements</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Improve GiST and R-tree index performance (Neil) </p></li><li class="listitem"><p> Improve the optimizer, including auto-resizing of hash joins (Tom) </p></li><li class="listitem"><p> Overhaul internal API in several areas </p></li><li class="listitem"><p> Change WAL record CRCs from 64-bit to 32-bit (Tom) </p><p> We determined that the extra cost of computing 64-bit CRCs was significant, and the gain in reliability too marginal to justify it. </p></li><li class="listitem"><p> Prevent writing large empty gaps in WAL pages (Tom) </p></li><li class="listitem"><p> Improve spinlock behavior on SMP machines, particularly Opterons (Tom) </p></li><li class="listitem"><p> Allow nonconsecutive index columns to be used in a multicolumn index (Tom) </p><p> For example, this allows an index on columns a,b,c to be used in a query with <code class="command">WHERE a = 4 and c = 10</code>. </p></li><li class="listitem"><p> Skip WAL logging for <code class="command">CREATE TABLE AS</code> / <code class="command">SELECT INTO</code> (Simon) </p><p> Since a crash during <code class="command">CREATE TABLE AS</code> would cause the table to be dropped during recovery, there is no reason to WAL log as the table is loaded. (Logging still happens if WAL archiving is enabled, however.) </p></li><li class="listitem"><p> Allow concurrent GiST index access (Teodor, Oleg) </p></li><li class="listitem"><p> Add configuration parameter <code class="varname">full_page_writes</code> to control writing full pages to WAL (Bruce) </p><p> To prevent partial disk writes from corrupting the database, <span class="productname">PostgreSQL</span> writes a complete copy of each database disk page to WAL the first time it is modified after a checkpoint. This option turns off that functionality for more speed. This is safe to use with battery-backed disk caches where partial page writes cannot happen. </p></li><li class="listitem"><p> Use <code class="literal">O_DIRECT</code> if available when using <code class="literal">O_SYNC</code> for <code class="varname">wal_sync_method</code> (Itagaki Takahiro) </p><p> <code class="literal">O_DIRECT</code> causes disk writes to bypass the kernel cache, and for WAL writes, this improves performance. </p></li><li class="listitem"><p> Improve <code class="command">COPY FROM</code> performance (Alon Goldshuv) </p><p> This was accomplished by reading <code class="command">COPY</code> input in larger chunks, rather than character by character. </p></li><li class="listitem"><p> Improve the performance of <code class="function">COUNT()</code>, <code class="function">SUM</code>, <code class="function">AVG()</code>, <code class="function">STDDEV()</code>, and <code class="function">VARIANCE()</code> (Neil, Tom) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.4"><div class="titlepage"><div><div><h4 class="title">E.253.3.2. Server Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Prevent problems due to transaction ID (XID) wraparound (Tom) </p><p> The server will now warn when the transaction counter approaches the wraparound point. If the counter becomes too close to wraparound, the server will stop accepting queries. This ensures that data is not lost before needed vacuuming is performed. </p></li><li class="listitem"><p> Fix problems with object IDs (OIDs) conflicting with existing system objects after the OID counter has wrapped around (Tom) </p></li><li class="listitem"><p> Add warning about the need to increase <code class="varname">max_fsm_relations</code> and <code class="varname">max_fsm_pages</code> during <code class="command">VACUUM</code> (Ron Mayer) </p></li><li class="listitem"><p> Add <code class="varname">temp_buffers</code> configuration parameter to allow users to determine the size of the local buffer area for temporary table access (Tom) </p></li><li class="listitem"><p> Add session start time and client IP address to <code class="literal">pg_stat_activity</code> (Magnus) </p></li><li class="listitem"><p> Adjust <code class="literal">pg_stat</code> views for bitmap scans (Tom) </p><p> The meanings of some of the fields have changed slightly. </p></li><li class="listitem"><p> Enhance <code class="literal">pg_locks</code> view (Tom) </p></li><li class="listitem"><p> Log queries for client-side <code class="command">PREPARE</code> and <code class="command">EXECUTE</code> (Simon) </p></li><li class="listitem"><p> Allow Kerberos name and user name case sensitivity to be specified in <code class="filename">postgresql.conf</code> (Magnus) </p></li><li class="listitem"><p> Add configuration parameter <code class="varname">krb_server_hostname</code> so that the server host name can be specified as part of service principal (Todd Kover) </p><p> If not set, any service principal matching an entry in the keytab can be used. This is new Kerberos matching behavior in this release. </p></li><li class="listitem"><p> Add <code class="varname">log_line_prefix</code> options for millisecond timestamps (<code class="literal">%m</code>) and remote host (<code class="literal">%h</code>) (Ed L.) </p></li><li class="listitem"><p> Add WAL logging for GiST indexes (Teodor, Oleg) </p><p> GiST indexes are now safe for crash and point-in-time recovery. </p></li><li class="listitem"><p> Remove old <code class="filename">*.backup</code> files when we do <code class="function">pg_stop_backup()</code> (Bruce) </p><p> This prevents a large number of <code class="filename">*.backup</code> files from existing in <code class="filename">pg_xlog/</code>. </p></li><li class="listitem"><p> Add configuration parameters to control TCP/IP keep-alive times for idle, interval, and count (Oliver Jowett) </p><p> These values can be changed to allow more rapid detection of lost client connections. </p></li><li class="listitem"><p> Add per-user and per-database connection limits (Petr Jelinek) </p><p> Using <code class="command">ALTER USER</code> and <code class="command">ALTER DATABASE</code>, limits can now be enforced on the maximum number of sessions that can concurrently connect as a specific user or to a specific database. Setting the limit to zero disables user or database connections. </p></li><li class="listitem"><p> Allow more than two gigabytes of shared memory and per-backend work memory on 64-bit machines (Koichi Suzuki) </p></li><li class="listitem"><p> New system catalog <code class="structname">pg_pltemplate</code> allows overriding obsolete procedural-language definitions in dump files (Tom) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.5"><div class="titlepage"><div><div><h4 class="title">E.253.3.3. Query Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Add temporary views (Koju Iijima, Neil) </p></li><li class="listitem"><p> Fix <code class="command">HAVING</code> without any aggregate functions or <code class="command">GROUP BY</code> so that the query returns a single group (Tom) </p><p> Previously, such a case would treat the <code class="command">HAVING</code> clause the same as a <code class="command">WHERE</code> clause. This was not per spec. </p></li><li class="listitem"><p> Add <code class="command">USING</code> clause to allow additional tables to be specified to <code class="command">DELETE</code> (Euler Taveira de Oliveira, Neil) </p><p> In prior releases, there was no clear method for specifying additional tables to be used for joins in a <code class="command">DELETE</code> statement. <code class="command">UPDATE</code> already has a <code class="literal">FROM</code> clause for this purpose. </p></li><li class="listitem"><p> Add support for <code class="literal">\x</code> hex escapes in backend and ecpg strings (Bruce) </p><p> This is just like the standard C <code class="literal">\x</code> escape syntax. Octal escapes were already supported. </p></li><li class="listitem"><p> Add <code class="command">BETWEEN SYMMETRIC</code> query syntax (Pavel Stehule) </p><p> This feature allows <code class="command">BETWEEN</code> comparisons without requiring the first value to be less than the second. For example, <code class="command">2 BETWEEN [ASYMMETRIC] 3 AND 1</code> returns false, while <code class="command">2 BETWEEN SYMMETRIC 3 AND 1</code> returns true. <code class="command">BETWEEN ASYMMETRIC</code> was already supported. </p></li><li class="listitem"><p> Add <code class="command">NOWAIT</code> option to <code class="command">SELECT ... FOR UPDATE/SHARE</code> (Hans-Juergen Schoenig) </p><p> While the <code class="varname">statement_timeout</code> configuration parameter allows a query taking more than a certain amount of time to be canceled, the <code class="command">NOWAIT</code> option allows a query to be canceled as soon as a <code class="command">SELECT ... FOR UPDATE/SHARE</code> command cannot immediately acquire a row lock. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.6"><div class="titlepage"><div><div><h4 class="title">E.253.3.4. Object Manipulation Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Track dependencies of shared objects (Alvaro) </p><p> <span class="productname">PostgreSQL</span> allows global tables (users, databases, tablespaces) to reference information in multiple databases. This addition adds dependency information for global tables, so, for example, user ownership can be tracked across databases, so a user who owns something in any database can no longer be removed. Dependency tracking already existed for database-local objects. </p></li><li class="listitem"><p> Allow limited <code class="command">ALTER OWNER</code> commands to be performed by the object owner (Stephen Frost) </p><p> Prior releases allowed only superusers to change object owners. Now, ownership can be transferred if the user executing the command owns the object and would be able to create it as the new owner (that is, the user is a member of the new owning role and that role has the CREATE permission that would be needed to create the object afresh). </p></li><li class="listitem"><p> Add <code class="command">ALTER</code> object <code class="command">SET SCHEMA</code> capability for some object types (tables, functions, types) (Bernd Helmle) </p><p> This allows objects to be moved to different schemas. </p></li><li class="listitem"><p> Add <code class="command">ALTER TABLE ENABLE/DISABLE TRIGGER</code> to disable triggers (Satoshi Nagayasu) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.7"><div class="titlepage"><div><div><h4 class="title">E.253.3.5. Utility Command Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Allow <code class="command">TRUNCATE</code> to truncate multiple tables in a single command (Alvaro) </p><p> Because of referential integrity checks, it is not allowed to truncate a table that is part of a referential integrity constraint. Using this new functionality, <code class="command">TRUNCATE</code> can be used to truncate such tables, if both tables involved in a referential integrity constraint are truncated in a single <code class="command">TRUNCATE</code> command. </p></li><li class="listitem"><p> Properly process carriage returns and line feeds in <code class="command">COPY CSV</code> mode (Andrew) </p><p> In release 8.0, carriage returns and line feeds in <code class="command">CSV COPY TO</code> were processed in an inconsistent manner. (This was documented on the TODO list.) </p></li><li class="listitem"><p> Add <code class="command">COPY WITH CSV HEADER</code> to allow a header line as the first line in <code class="command">COPY</code> (Andrew) </p><p> This allows handling of the common <code class="command">CSV</code> usage of placing the column names on the first line of the data file. For <code class="command">COPY TO</code>, the first line contains the column names, and for <code class="command">COPY FROM</code>, the first line is ignored. </p></li><li class="listitem"><p> On Windows, display better sub-second precision in <code class="command">EXPLAIN ANALYZE</code> (Magnus) </p></li><li class="listitem"><p> Add trigger duration display to <code class="command">EXPLAIN ANALYZE</code> (Tom) </p><p> Prior releases included trigger execution time as part of the total execution time, but did not show it separately. It is now possible to see how much time is spent in each trigger. </p></li><li class="listitem"><p> Add support for <code class="literal">\x</code> hex escapes in <code class="command">COPY</code> (Sergey Ten) </p><p> Previous releases only supported octal escapes. </p></li><li class="listitem"><p> Make <code class="command">SHOW ALL</code> include variable descriptions (Matthias Schmidt) </p><p> <code class="command">SHOW</code> varname still only displays the variable's value and does not include the description. </p></li><li class="listitem"><p> Make <span class="application">initdb</span> create a new standard database called <code class="literal">postgres</code>, and convert utilities to use <code class="literal">postgres</code> rather than <code class="literal">template1</code> for standard lookups (Dave) </p><p> In prior releases, <code class="literal">template1</code> was used both as a default connection for utilities like <span class="application">createuser</span>, and as a template for new databases. This caused <code class="command">CREATE DATABASE</code> to sometimes fail, because a new database cannot be created if anyone else is in the template database. With this change, the default connection database is now <code class="literal">postgres</code>, meaning it is much less likely someone will be using <code class="literal">template1</code> during <code class="command">CREATE DATABASE</code>. </p></li><li class="listitem"><p> Create new <span class="application">reindexdb</span> command-line utility by moving <code class="filename">/contrib/reindexdb</code> into the server (Euler Taveira de Oliveira) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.8"><div class="titlepage"><div><div><h4 class="title">E.253.3.6. Data Type and Function Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Add <code class="function">MAX()</code> and <code class="function">MIN()</code> aggregates for array types (Koju Iijima) </p></li><li class="listitem"><p> Fix <code class="function">to_date()</code> and <code class="function">to_timestamp()</code> to behave reasonably when <code class="literal">CC</code> and <code class="literal">YY</code> fields are both used (Karel Zak) </p><p> If the format specification contains <code class="literal">CC</code> and a year specification is <code class="literal">YYY</code> or longer, ignore the <code class="literal">CC</code>. If the year specification is <code class="literal">YY</code> or shorter, interpret <code class="literal">CC</code> as the previous century. </p></li><li class="listitem"><p> Add <code class="function">md5(bytea)</code> (Abhijit Menon-Sen) </p><p> <code class="function">md5(text)</code> already existed. </p></li><li class="listitem"><p> Add support for <code class="command">numeric ^ numeric</code> based on <code class="function">power(numeric, numeric)</code> </p><p> The function already existed, but there was no operator assigned to it. </p></li><li class="listitem"><p> Fix <code class="type">NUMERIC</code> modulus by properly truncating the quotient during computation (Bruce) </p><p> In previous releases, modulus for large values sometimes returned negative results due to rounding of the quotient. </p></li><li class="listitem"><p> Add a function <code class="function">lastval()</code> (Dennis Björklund) </p><p> <code class="function">lastval()</code> is a simplified version of <code class="function">currval()</code>. It automatically determines the proper sequence name based on the most recent <code class="function">nextval()</code> or <code class="function">setval()</code> call performed by the current session. </p></li><li class="listitem"><p> Add <code class="function">to_timestamp(DOUBLE PRECISION) (Michael Glaesemann)</code> </p><p> Converts Unix seconds since 1970 to a <code class="type">TIMESTAMP WITH TIMEZONE</code>. </p></li><li class="listitem"><p> Add <code class="function">pg_postmaster_start_time()</code> function (Euler Taveira de Oliveira, Matthias Schmidt) </p></li><li class="listitem"><p> Allow the full use of time zone names in <code class="command">AT TIME ZONE</code>, not just the short list previously available (Magnus) </p><p> Previously, only a predefined list of time zone names were supported by <code class="command">AT TIME ZONE</code>. Now any supported time zone name can be used, e.g.: </p><pre class="programlisting"> SELECT CURRENT_TIMESTAMP AT TIME ZONE 'Europe/London'; </pre><p> In the above query, the time zone used is adjusted based on the daylight saving time rules that were in effect on the supplied date. </p></li><li class="listitem"><p> Add <code class="function">GREATEST()</code> and <code class="function">LEAST()</code> variadic functions (Pavel Stehule) </p><p> These functions take a variable number of arguments and return the greatest or least value among the arguments. </p></li><li class="listitem"><p> Add <code class="function">pg_column_size()</code> (Mark Kirkwood) </p><p> This returns storage size of a column, which might be compressed. </p></li><li class="listitem"><p> Add <code class="function">regexp_replace()</code> (Atsushi Ogawa) </p><p> This allows regular expression replacement, like sed. An optional flag argument allows selection of global (replace all) and case-insensitive modes. </p></li><li class="listitem"><p> Fix interval division and multiplication (Bruce) </p><p> Previous versions sometimes returned unjustified results, like <code class="command">'4 months'::interval / 5</code> returning <code class="command">'1 mon -6 days'</code>. </p></li><li class="listitem"><p> Fix roundoff behavior in timestamp, time, and interval output (Tom) </p><p> This fixes some cases in which the seconds field would be shown as <code class="literal">60</code> instead of incrementing the higher-order fields. </p></li><li class="listitem"><p> Add a separate day field to type <code class="type">interval</code> so a one day interval can be distinguished from a 24 hour interval (Michael Glaesemann) </p><p> Days that contain a daylight saving time adjustment are not 24 hours long, but typically 23 or 25 hours. This change creates a conceptual distinction between intervals of <span class="quote">“<span class="quote">so many days</span>”</span> and intervals of <span class="quote">“<span class="quote">so many hours</span>”</span>. Adding <code class="literal">1 day</code> to a timestamp now gives the same local time on the next day even if a daylight saving time adjustment occurs between, whereas adding <code class="literal">24 hours</code> will give a different local time when this happens. For example, under US DST rules: </p><pre class="programlisting"> '2005-04-03 00:00:00-05' + '1 day' = '2005-04-04 00:00:00-04' '2005-04-03 00:00:00-05' + '24 hours' = '2005-04-04 01:00:00-04' </pre><p> </p></li><li class="listitem"><p> Add <code class="function">justify_days()</code> and <code class="function">justify_hours()</code> (Michael Glaesemann) </p><p> These functions, respectively, adjust days to an appropriate number of full months and days, and adjust hours to an appropriate number of full days and hours. </p></li><li class="listitem"><p> Move <code class="filename">/contrib/dbsize</code> into the backend, and rename some of the functions (Dave Page, Andreas Pflug) </p><p> </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p> <code class="function">pg_tablespace_size()</code> </p></li><li class="listitem"><p> <code class="function">pg_database_size()</code> </p></li><li class="listitem"><p> <code class="function">pg_relation_size()</code> </p></li><li class="listitem"><p> <code class="function">pg_total_relation_size()</code> </p></li><li class="listitem"><p> <code class="function">pg_size_pretty()</code> </p></li></ul></div><p> </p><p> <code class="function">pg_total_relation_size()</code> includes indexes and TOAST tables. </p></li><li class="listitem"><p> Add functions for read-only file access to the cluster directory (Dave Page, Andreas Pflug) </p><p> </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p> <code class="function">pg_stat_file()</code> </p></li><li class="listitem"><p> <code class="function">pg_read_file()</code> </p></li><li class="listitem"><p> <code class="function">pg_ls_dir()</code> </p></li></ul></div><p> </p></li><li class="listitem"><p> Add <code class="function">pg_reload_conf()</code> to force reloading of the configuration files (Dave Page, Andreas Pflug) </p></li><li class="listitem"><p> Add <code class="function">pg_rotate_logfile()</code> to force rotation of the server log file (Dave Page, Andreas Pflug) </p></li><li class="listitem"><p> Change <code class="literal">pg_stat_*</code> views to include TOAST tables (Tom) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.9"><div class="titlepage"><div><div><h4 class="title">E.253.3.7. Encoding and Locale Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Rename some encodings to be more consistent and to follow international standards (Bruce) </p><p> </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p> <code class="literal">UNICODE</code> is now <code class="literal">UTF8</code> </p></li><li class="listitem"><p> <code class="literal">ALT</code> is now <code class="literal">WIN866</code> </p></li><li class="listitem"><p> <code class="literal">WIN</code> is now <code class="literal">WIN1251</code> </p></li><li class="listitem"><p> <code class="literal">TCVN</code> is now <code class="literal">WIN1258</code> </p></li></ul></div><p> </p><p> The original names still work. </p></li><li class="listitem"><p> Add support for <code class="literal">WIN1252</code> encoding (Roland Volkmann) </p></li><li class="listitem"><p> Add support for four-byte <code class="literal">UTF8</code> characters (John Hansen) </p><p> Previously only one, two, and three-byte <code class="literal">UTF8</code> characters were supported. This is particularly important for support for some Chinese character sets. </p></li><li class="listitem"><p> Allow direct conversion between <code class="literal">EUC_JP</code> and <code class="literal">SJIS</code> to improve performance (Atsushi Ogawa) </p></li><li class="listitem"><p> Allow the UTF8 encoding to work on Windows (Magnus) </p><p> This is done by mapping UTF8 to the Windows-native UTF16 implementation. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.10"><div class="titlepage"><div><div><h4 class="title">E.253.3.8. General Server-Side Language Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Fix <code class="command">ALTER LANGUAGE RENAME</code> (Sergey Yatskevich) </p></li><li class="listitem"><p> Allow function characteristics, like strictness and volatility, to be modified via <code class="command">ALTER FUNCTION</code> (Neil) </p></li><li class="listitem"><p> Increase the maximum number of function arguments to 100 (Tom) </p></li><li class="listitem"><p> Allow SQL and PL/pgSQL functions to use <code class="command">OUT</code> and <code class="command">INOUT</code> parameters (Tom) </p><p> <code class="command">OUT</code> is an alternate way for a function to return values. Instead of using <code class="command">RETURN</code>, values can be returned by assigning to parameters declared as <code class="command">OUT</code> or <code class="command">INOUT</code>. This is notationally simpler in some cases, particularly so when multiple values need to be returned. While returning multiple values from a function was possible in previous releases, this greatly simplifies the process. (The feature will be extended to other server-side languages in future releases.) </p></li><li class="listitem"><p> Move language handler functions into the <code class="literal">pg_catalog</code> schema </p><p> This makes it easier to drop the public schema if desired. </p></li><li class="listitem"><p> Add <code class="function">SPI_getnspname()</code> to SPI (Neil) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.11"><div class="titlepage"><div><div><h4 class="title">E.253.3.9. PL/pgSQL Server-Side Language Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Overhaul the memory management of PL/pgSQL functions (Neil) </p><p> The parsetree of each function is now stored in a separate memory context. This allows this memory to be easily reclaimed when it is no longer needed. </p></li><li class="listitem"><p> Check function syntax at <code class="command">CREATE FUNCTION</code> time, rather than at runtime (Neil) </p><p> Previously, most syntax errors were reported only when the function was executed. </p></li><li class="listitem"><p> Allow <code class="command">OPEN</code> to open non-<code class="command">SELECT</code> queries like <code class="command">EXPLAIN</code> and <code class="command">SHOW</code> (Tom) </p></li><li class="listitem"><p> No longer require functions to issue a <code class="command">RETURN</code> statement (Tom) </p><p> This is a byproduct of the newly added <code class="command">OUT</code> and <code class="command">INOUT</code> functionality. <code class="command">RETURN</code> can be omitted when it is not needed to provide the function's return value. </p></li><li class="listitem"><p> Add support for an optional <code class="command">INTO</code> clause to PL/pgSQL's <code class="command">EXECUTE</code> statement (Pavel Stehule, Neil) </p></li><li class="listitem"><p> Make <code class="command">CREATE TABLE AS</code> set <code class="command">ROW_COUNT</code> (Tom) </p></li><li class="listitem"><p> Define <code class="literal">SQLSTATE</code> and <code class="literal">SQLERRM</code> to return the <code class="literal">SQLSTATE</code> and error message of the current exception (Pavel Stehule, Neil) </p><p> These variables are only defined inside exception blocks. </p></li><li class="listitem"><p> Allow the parameters to the <code class="command">RAISE</code> statement to be expressions (Pavel Stehule, Neil) </p></li><li class="listitem"><p> Add a loop <code class="command">CONTINUE</code> statement (Pavel Stehule, Neil) </p></li><li class="listitem"><p> Allow block and loop labels (Pavel Stehule) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.12"><div class="titlepage"><div><div><h4 class="title">E.253.3.10. PL/Perl Server-Side Language Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Allow large result sets to be returned efficiently (Abhijit Menon-Sen) </p><p> This allows functions to use <code class="function">return_next()</code> to avoid building the entire result set in memory. </p></li><li class="listitem"><p> Allow one-row-at-a-time retrieval of query results (Abhijit Menon-Sen) </p><p> This allows functions to use <code class="function">spi_query()</code> and <code class="function">spi_fetchrow()</code> to avoid accumulating the entire result set in memory. </p></li><li class="listitem"><p> Force PL/Perl to handle strings as <code class="literal">UTF8</code> if the server encoding is <code class="literal">UTF8</code> (David Kamholz) </p></li><li class="listitem"><p> Add a validator function for PL/Perl (Andrew) </p><p> This allows syntax errors to be reported at definition time, rather than execution time. </p></li><li class="listitem"><p> Allow PL/Perl to return a Perl array when the function returns an array type (Andrew) </p><p> This basically maps <span class="productname">PostgreSQL</span> arrays to Perl arrays. </p></li><li class="listitem"><p> Allow Perl nonfatal warnings to generate <code class="command">NOTICE</code> messages (Andrew) </p></li><li class="listitem"><p> Allow Perl's <code class="literal">strict</code> mode to be enabled (Andrew) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.13"><div class="titlepage"><div><div><h4 class="title">E.253.3.11. <span class="application">psql</span> Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Add <code class="command">\set ON_ERROR_ROLLBACK</code> to allow statements in a transaction to error without affecting the rest of the transaction (Greg Sabino Mullane) </p><p> This is basically implemented by wrapping every statement in a sub-transaction. </p></li><li class="listitem"><p> Add support for <code class="literal">\x</code> hex strings in <span class="application">psql</span> variables (Bruce) </p><p> Octal escapes were already supported. </p></li><li class="listitem"><p> Add support for <code class="command">troff -ms</code> output format (Roger Leigh) </p></li><li class="listitem"><p> Allow the history file location to be controlled by <code class="envar">HISTFILE</code> (Andreas Seltenreich) </p><p> This allows configuration of per-database history storage. </p></li><li class="listitem"><p> Prevent <code class="command">\x</code> (expanded mode) from affecting the output of <code class="command">\d tablename</code> (Neil) </p></li><li class="listitem"><p> Add <code class="option">-L</code> option to <span class="application">psql</span> to log sessions (Lorne Sunley) </p><p> This option was added because some operating systems do not have simple command-line activity logging functionality. </p></li><li class="listitem"><p> Make <code class="command">\d</code> show the tablespaces of indexes (Qingqing Zhou) </p></li><li class="listitem"><p> Allow <span class="application">psql</span> help (<code class="command">\h</code>) to make a best guess on the proper help information (Greg Sabino Mullane) </p><p> This allows the user to just add <code class="command">\h</code> to the front of the syntax error query and get help on the supported syntax. Previously any additional query text beyond the command name had to be removed to use <code class="command">\h</code>. </p></li><li class="listitem"><p> Add <code class="command">\pset numericlocale</code> to allow numbers to be output in a locale-aware format (Eugen Nedelcu) </p><p> For example, using <code class="literal">C</code> locale <code class="literal">100000</code> would be output as <code class="literal">100,000.0</code> while a European locale might output this value as <code class="literal">100.000,0</code>. </p></li><li class="listitem"><p> Make startup banner show both server version number and <span class="application">psql</span>'s version number, when they are different (Bruce) </p><p> Also, a warning will be shown if the server and <span class="application">psql</span> are from different major releases. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.14"><div class="titlepage"><div><div><h4 class="title">E.253.3.12. <span class="application">pg_dump</span> Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Add <code class="option">-n</code> / <code class="option">--schema</code> switch to <span class="application">pg_restore</span> (Richard van den Berg) </p><p> This allows just the objects in a specified schema to be restored. </p></li><li class="listitem"><p> Allow <span class="application">pg_dump</span> to dump large objects even in text mode (Tom) </p><p> With this change, large objects are now always dumped; the former <code class="option">-b</code> switch is a no-op. </p></li><li class="listitem"><p> Allow <span class="application">pg_dump</span> to dump a consistent snapshot of large objects (Tom) </p></li><li class="listitem"><p> Dump comments for large objects (Tom) </p></li><li class="listitem"><p> Add <code class="option">--encoding</code> to <span class="application">pg_dump</span> (Magnus Hagander) </p><p> This allows a database to be dumped in an encoding that is different from the server's encoding. This is valuable when transferring the dump to a machine with a different encoding. </p></li><li class="listitem"><p> Rely on <code class="structname">pg_pltemplate</code> for procedural languages (Tom) </p><p> If the call handler for a procedural language is in the <code class="literal">pg_catalog</code> schema, <span class="application">pg_dump</span> does not dump the handler. Instead, it dumps the language using just <code class="command">CREATE LANGUAGE <em class="replaceable"><code>name</code></em></code>, relying on the <code class="structname">pg_pltemplate</code> catalog to provide the language's creation parameters at load time. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.15"><div class="titlepage"><div><div><h4 class="title">E.253.3.13. <span class="application">libpq</span> Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Add a <code class="envar">PGPASSFILE</code> environment variable to specify the password file's filename (Andrew) </p></li><li class="listitem"><p> Add <code class="function">lo_create()</code>, that is similar to <code class="function">lo_creat()</code> but allows the OID of the large object to be specified (Tom) </p></li><li class="listitem"><p> Make <span class="application">libpq</span> consistently return an error to the client application on <code class="function">malloc()</code> failure (Neil) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.16"><div class="titlepage"><div><div><h4 class="title">E.253.3.14. Source Code Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Fix <span class="application">pgxs</span> to support building against a relocated installation </p></li><li class="listitem"><p> Add spinlock support for the Itanium processor using Intel compiler (Vikram Kalsi) </p></li><li class="listitem"><p> Add Kerberos 5 support for Windows (Magnus) </p></li><li class="listitem"><p> Add Chinese FAQ (laser@pgsqldb.com) </p></li><li class="listitem"><p> Rename Rendezvous to Bonjour to match OS/X feature renaming (Bruce) </p></li><li class="listitem"><p> Add support for <code class="literal">fsync_writethrough</code> on macOS (Chris Campbell) </p></li><li class="listitem"><p> Streamline the passing of information within the server, the optimizer, and the lock system (Tom) </p></li><li class="listitem"><p> Allow <span class="application">pg_config</span> to be compiled using MSVC (Andrew) </p><p> This is required to build DBD::Pg using <span class="application">MSVC</span>. </p></li><li class="listitem"><p> Remove support for Kerberos V4 (Magnus) </p><p> Kerberos 4 had security vulnerabilities and is no longer maintained. </p></li><li class="listitem"><p> Code cleanups (Coverity static analysis performed by EnterpriseDB) </p></li><li class="listitem"><p> Modify <code class="filename">postgresql.conf</code> to use documentation defaults <code class="literal">on</code>/<code class="literal">off</code> rather than <code class="literal">true</code>/<code class="literal">false</code> (Bruce) </p></li><li class="listitem"><p> Enhance <span class="application">pg_config</span> to be able to report more build-time values (Tom) </p></li><li class="listitem"><p> Allow <span class="application">libpq</span> to be built thread-safe on Windows (Dave Page) </p></li><li class="listitem"><p> Allow IPv6 connections to be used on Windows (Andrew) </p></li><li class="listitem"><p> Add Server Administration documentation about I/O subsystem reliability (Bruce) </p></li><li class="listitem"><p> Move private declarations from <code class="filename">gist.h</code> to <code class="filename">gist_private.h</code> (Neil) </p><p> In previous releases, <code class="filename">gist.h</code> contained both the public GiST API (intended for use by authors of GiST index implementations) as well as some private declarations used by the implementation of GiST itself. The latter have been moved to a separate file, <code class="filename">gist_private.h</code>. Most GiST index implementations should be unaffected. </p></li><li class="listitem"><p> Overhaul GiST memory management (Neil) </p><p> GiST methods are now always invoked in a short-lived memory context. Therefore, memory allocated via <code class="function">palloc()</code> will be reclaimed automatically, so GiST index implementations do not need to manually release allocated memory via <code class="function">pfree()</code>. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.257.5.17"><div class="titlepage"><div><div><h4 class="title">E.253.3.15. Contrib Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Add <code class="filename">/contrib/pg_buffercache</code> contrib module (Mark Kirkwood) </p><p> This displays the contents of the buffer cache, for debugging and performance tuning purposes. </p></li><li class="listitem"><p> Remove <code class="filename">/contrib/array</code> because it is obsolete (Tom) </p></li><li class="listitem"><p> Clean up the <code class="filename">/contrib/lo</code> module (Tom) </p></li><li class="listitem"><p> Move <code class="filename">/contrib/findoidjoins</code> to <code class="filename">/src/tools</code> (Tom) </p></li><li class="listitem"><p> Remove the <code class="literal"><<</code>, <code class="literal">>></code>, <code class="literal">&<</code>, and <code class="literal">&></code> operators from <code class="filename">/contrib/cube</code> </p><p> These operators were not useful. </p></li><li class="listitem"><p> Improve <code class="filename">/contrib/btree_gist</code> (Janko Richter) </p></li><li class="listitem"><p> Improve <code class="filename">/contrib/pgbench</code> (Tomoaki Sato, Tatsuo) </p><p> There is now a facility for testing with SQL command scripts given by the user, instead of only a hard-wired command sequence. </p></li><li class="listitem"><p> Improve <code class="filename">/contrib/pgcrypto</code> (Marko Kreen) </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p> Implementation of OpenPGP symmetric-key and public-key encryption </p><p> Both RSA and Elgamal public-key algorithms are supported. </p></li><li class="listitem"><p> Stand alone build: include SHA256/384/512 hashes, Fortuna PRNG </p></li><li class="listitem"><p> OpenSSL build: support 3DES, use internal AES with OpenSSL < 0.9.7 </p></li><li class="listitem"><p> Take build parameters (OpenSSL, zlib) from <code class="filename">configure</code> result </p><p> There is no need to edit the <code class="filename">Makefile</code> anymore. </p></li><li class="listitem"><p> Remove support for <code class="filename">libmhash</code> and <code class="filename">libmcrypt</code> </p></li></ul></div></li></ul></div></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="release-8-1-1.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="release.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="release-8-0-26.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">E.252. 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