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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.311. Release 7.4</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-7-4-1.html" title="E.310. Release 7.4.1" /><link rel="next" href="release-7-3-21.html" title="E.312. Release 7.3.21" /></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.311. Release 7.4</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="release-7-4-1.html" title="E.310. Release 7.4.1">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-7-3-21.html" title="E.312. Release 7.3.21">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="RELEASE-7-4"><div class="titlepage"><div><div><h2 class="title" style="clear: both">E.311. Release 7.4</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="release-7-4.html#id-1.11.6.315.3">E.311.1. Overview</a></span></dt><dt><span class="sect2"><a href="release-7-4.html#id-1.11.6.315.4">E.311.2. Migration to Version 7.4</a></span></dt><dt><span class="sect2"><a href="release-7-4.html#id-1.11.6.315.5">E.311.3. Changes</a></span></dt></dl></div><p><strong>Release date: </strong>2003-11-17</p><div class="sect2" id="id-1.11.6.315.3"><div class="titlepage"><div><div><h3 class="title">E.311.1. Overview</h3></div></div></div><p> Major changes in this release: </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"> <code class="literal">IN</code> / <code class="literal">NOT IN</code> subqueries are now much more efficient </span></dt><dd><p> In previous releases, <code class="literal">IN</code>/<code class="literal">NOT IN</code> subqueries were joined to the upper query by sequentially scanning the subquery looking for a match. The 7.4 code uses the same sophisticated techniques used by ordinary joins and so is much faster. An <code class="literal">IN</code> will now usually be as fast as or faster than an equivalent <code class="literal">EXISTS</code> subquery; this reverses the conventional wisdom that applied to previous releases. </p></dd><dt><span class="term"> Improved <code class="literal">GROUP BY</code> processing by using hash buckets </span></dt><dd><p> In previous releases, rows to be grouped had to be sorted first. The 7.4 code can do <code class="literal">GROUP BY</code> without sorting, by accumulating results into a hash table with one entry per group. It will still use the sort technique, however, if the hash table is estimated to be too large to fit in <code class="varname">sort_mem</code>. </p></dd><dt><span class="term"> New multikey hash join capability </span></dt><dd><p> In previous releases, hash joins could only occur on single keys. This release allows multicolumn hash joins. </p></dd><dt><span class="term"> Queries using the explicit <code class="literal">JOIN</code> syntax are now better optimized </span></dt><dd><p> Prior releases evaluated queries using the explicit <code class="literal">JOIN</code> syntax only in the order implied by the syntax. 7.4 allows full optimization of these queries, meaning the optimizer considers all possible join orderings and chooses the most efficient. Outer joins, however, must still follow the declared ordering. </p></dd><dt><span class="term"> Faster and more powerful regular expression code </span></dt><dd><p> The entire regular expression module has been replaced with a new version by Henry Spencer, originally written for Tcl. The code greatly improves performance and supports several flavors of regular expressions. </p></dd><dt><span class="term"> Function-inlining for simple SQL functions </span></dt><dd><p> Simple SQL functions can now be inlined by including their SQL in the main query. This improves performance by eliminating per-call overhead. That means simple SQL functions now behave like macros. </p></dd><dt><span class="term"> Full support for IPv6 connections and IPv6 address data types </span></dt><dd><p> Previous releases allowed only IPv4 connections, and the IP data types only supported IPv4 addresses. This release adds full IPv6 support in both of these areas. </p></dd><dt><span class="term"> Major improvements in SSL performance and reliability </span></dt><dd><p> Several people very familiar with the SSL API have overhauled our SSL code to improve SSL key negotiation and error recovery. </p></dd><dt><span class="term"> Make free space map efficiently reuse empty index pages, and other free space management improvements </span></dt><dd><p> In previous releases, B-tree index pages that were left empty because of deleted rows could only be reused by rows with index values similar to the rows originally indexed on that page. In 7.4, <code class="command">VACUUM</code> records empty index pages and allows them to be reused for any future index rows. </p></dd><dt><span class="term"> SQL-standard information schema </span></dt><dd><p> The information schema provides a standardized and stable way to access information about the schema objects defined in a database. </p></dd><dt><span class="term"> Cursors conform more closely to the SQL standard </span></dt><dd><p> The commands <code class="command">FETCH</code> and <code class="command">MOVE</code> have been overhauled to conform more closely to the SQL standard. </p></dd><dt><span class="term"> Cursors can exist outside transactions </span></dt><dd><p> These cursors are also called holdable cursors. </p></dd><dt><span class="term"> New client-to-server protocol </span></dt><dd><p> The new protocol adds error codes, more status information, faster startup, better support for binary data transmission, parameter values separated from SQL commands, prepared statements available at the protocol level, and cleaner recovery from <code class="command">COPY</code> failures. The older protocol is still supported by both server and clients. </p></dd><dt><span class="term"> <span class="application">libpq</span> and <span class="application">ECPG</span> applications are now fully thread-safe </span></dt><dd><p> While previous <span class="application">libpq</span> releases already supported threads, this release improves thread safety by fixing some non-thread-safe code that was used during database connection startup. The <code class="command">configure</code> option <code class="option">--enable-thread-safety</code> must be used to enable this feature. </p></dd><dt><span class="term"> New version of full-text indexing </span></dt><dd><p> A new full-text indexing suite is available in <code class="filename">contrib/tsearch2</code>. </p></dd><dt><span class="term"> New autovacuum tool </span></dt><dd><p> The new autovacuum tool in <code class="filename">contrib/autovacuum</code> monitors the database statistics tables for <code class="command">INSERT</code>/<code class="command">UPDATE</code>/<code class="command">DELETE</code> activity and automatically vacuums tables when needed. </p></dd><dt><span class="term"> Array handling has been improved and moved into the server core </span></dt><dd><p> Many array limitations have been removed, and arrays behave more like fully-supported data types. </p></dd></dl></div></div><div class="sect2" id="id-1.11.6.315.4"><div class="titlepage"><div><div><h3 class="title">E.311.2. Migration to Version 7.4</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> Observe the following incompatibilities: </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> The server-side autocommit setting was removed and reimplemented in client applications and languages. Server-side autocommit was causing too many problems with languages and applications that wanted to control their own autocommit behavior, so autocommit was removed from the server and added to individual client APIs as appropriate. </p></li><li class="listitem"><p> Error message wording has changed substantially in this release. Significant effort was invested to make the messages more consistent and user-oriented. If your applications try to detect different error conditions by parsing the error message, you are strongly encouraged to use the new error code facility instead. </p></li><li class="listitem"><p> Inner joins using the explicit <code class="literal">JOIN</code> syntax might behave differently because they are now better optimized. </p></li><li class="listitem"><p> A number of server configuration parameters have been renamed for clarity, primarily those related to logging. </p></li><li class="listitem"><p> <code class="literal">FETCH 0</code> or <code class="literal">MOVE 0</code> now does nothing. In prior releases, <code class="literal">FETCH 0</code> would fetch all remaining rows, and <code class="literal">MOVE 0</code> would move to the end of the cursor. </p></li><li class="listitem"><p> <code class="command">FETCH</code> and <code class="command">MOVE</code> now return the actual number of rows fetched/moved, or zero if at the beginning/end of the cursor. Prior releases would return the row count passed to the command, not the number of rows actually fetched or moved. </p></li><li class="listitem"><p> <code class="command">COPY</code> now can process files that use carriage-return or carriage-return/line-feed end-of-line sequences. Literal carriage-returns and line-feeds are no longer accepted in data values; use <code class="literal">\r</code> and <code class="literal">\n</code> instead. </p></li><li class="listitem"><p> Trailing spaces are now trimmed when converting from type <code class="type">char(<em class="replaceable"><code>n</code></em>)</code> to <code class="type">varchar(<em class="replaceable"><code>n</code></em>)</code> or <code class="type">text</code>. This is what most people always expected to happen anyway. </p></li><li class="listitem"><p> The data type <code class="type">float(<em class="replaceable"><code>p</code></em>)</code> now measures <em class="replaceable"><code>p</code></em> in binary digits, not decimal digits. The new behavior follows the SQL standard. </p></li><li class="listitem"><p> Ambiguous date values now must match the ordering specified by the <code class="varname">datestyle</code> setting. In prior releases, a date specification of <code class="literal">10/20/03</code> was interpreted as a date in October even if <code class="varname">datestyle</code> specified that the day should be first. 7.4 will throw an error if a date specification is invalid for the current setting of <code class="varname">datestyle</code>. </p></li><li class="listitem"><p> The functions <code class="function">oidrand</code>, <code class="function">oidsrand</code>, and <code class="function">userfntest</code> have been removed. These functions were determined to be no longer useful. </p></li><li class="listitem"><p> String literals specifying time-varying date/time values, such as <code class="literal">'now'</code> or <code class="literal">'today'</code> will no longer work as expected in column default expressions; they now cause the time of the table creation to be the default, not the time of the insertion. Functions such as <code class="function">now()</code>, <code class="function">current_timestamp</code>, or <code class="function">current_date</code> should be used instead. </p><p> In previous releases, there was special code so that strings such as <code class="literal">'now'</code> were interpreted at <code class="command">INSERT</code> time and not at table creation time, but this work around didn't cover all cases. Release 7.4 now requires that defaults be defined properly using functions such as <code class="function">now()</code> or <code class="function">current_timestamp</code>. These will work in all situations. </p></li><li class="listitem"><p> The dollar sign (<code class="literal">$</code>) is no longer allowed in operator names. It can instead be a non-first character in identifiers. This was done to improve compatibility with other database systems, and to avoid syntax problems when parameter placeholders (<code class="literal">$<em class="replaceable"><code>n</code></em></code>) are written adjacent to operators. </p></li></ul></div></div><div class="sect2" id="id-1.11.6.315.5"><div class="titlepage"><div><div><h3 class="title">E.311.3. Changes</h3></div></div></div><p> Below you will find a detailed account of the changes between release 7.4 and the previous major release. </p><div class="sect3" id="id-1.11.6.315.5.3"><div class="titlepage"><div><div><h4 class="title">E.311.3.1. Server Operation Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Allow IPv6 server connections (Nigel Kukard, Johan Jordaan, Bruce, Tom, Kurt Roeckx, Andrew Dunstan) </p></li><li class="listitem"><p> Fix SSL to handle errors cleanly (Nathan Mueller) </p><p> In prior releases, certain SSL API error reports were not handled correctly. This release fixes those problems. </p></li><li class="listitem"><p> SSL protocol security and performance improvements (Sean Chittenden) </p><p> SSL key renegotiation was happening too frequently, causing poor SSL performance. Also, initial key handling was improved. </p></li><li class="listitem"><p> Print lock information when a deadlock is detected (Tom) </p><p> This allows easier debugging of deadlock situations. </p></li><li class="listitem"><p> Update <code class="filename">/tmp</code> socket modification times regularly to avoid their removal (Tom) </p><p> This should help prevent <code class="filename">/tmp</code> directory cleaner administration scripts from removing server socket files. </p></li><li class="listitem"><p>Enable PAM for macOS (Aaron Hillegass)</p></li><li class="listitem"><p>Make B-tree indexes fully WAL-safe (Tom)</p><p> In prior releases, under certain rare cases, a server crash could cause B-tree indexes to become corrupt. This release removes those last few rare cases. </p></li><li class="listitem"><p>Allow B-tree index compaction and empty page reuse (Tom)</p></li><li class="listitem"><p> Fix inconsistent index lookups during split of first root page (Tom) </p><p> In prior releases, when a single-page index split into two pages, there was a brief period when another database session could miss seeing an index entry. This release fixes that rare failure case. </p></li><li class="listitem"><p>Improve free space map allocation logic (Tom)</p></li><li class="listitem"><p>Preserve free space information between server restarts (Tom)</p><p> In prior releases, the free space map was not saved when the postmaster was stopped, so newly started servers had no free space information. This release saves the free space map, and reloads it when the server is restarted. </p></li><li class="listitem"><p>Add start time to <code class="literal">pg_stat_activity</code> (Neil)</p></li><li class="listitem"><p>New code to detect corrupt disk pages; erase with <code class="varname">zero_damaged_pages</code> (Tom)</p></li><li class="listitem"><p>New client/server protocol: faster, no username length limit, allow clean exit from <code class="command">COPY</code> (Tom)</p></li><li class="listitem"><p>Add transaction status, table ID, column ID to client/server protocol (Tom)</p></li><li class="listitem"><p>Add binary I/O to client/server protocol (Tom)</p></li><li class="listitem"><p>Remove autocommit server setting; move to client applications (Tom)</p></li><li class="listitem"><p>New error message wording, error codes, and three levels of error detail (Tom, Joe, Peter)</p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.4"><div class="titlepage"><div><div><h4 class="title">E.311.3.2. Performance Improvements</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Add hashing for <code class="literal">GROUP BY</code> aggregates (Tom)</p></li><li class="listitem"><p>Make nested-loop joins be smarter about multicolumn indexes (Tom)</p></li><li class="listitem"><p>Allow multikey hash joins (Tom)</p></li><li class="listitem"><p>Improve constant folding (Tom)</p></li><li class="listitem"><p>Add ability to inline simple SQL functions (Tom)</p></li><li class="listitem"><p>Reduce memory usage for queries using complex functions (Tom)</p><p> In prior releases, functions returning allocated memory would not free it until the query completed. This release allows the freeing of function-allocated memory when the function call completes, reducing the total memory used by functions. </p></li><li class="listitem"><p>Improve GEQO optimizer performance (Tom)</p><p> This release fixes several inefficiencies in the way the GEQO optimizer manages potential query paths. </p></li><li class="listitem"><p> Allow <code class="literal">IN</code>/<code class="literal">NOT IN</code> to be handled via hash tables (Tom) </p></li><li class="listitem"><p> Improve <code class="literal">NOT IN (<em class="replaceable"><code>subquery</code></em>)</code> performance (Tom) </p></li><li class="listitem"><p> Allow most <code class="literal">IN</code> subqueries to be processed as joins (Tom) </p></li><li class="listitem"><p> Pattern matching operations can use indexes regardless of locale (Peter) </p><p> There is no way for non-ASCII locales to use the standard indexes for <code class="literal">LIKE</code> comparisons. This release adds a way to create a special index for <code class="literal">LIKE</code>. </p></li><li class="listitem"><p>Allow the postmaster to preload libraries using <code class="varname">preload_libraries</code> (Joe)</p><p> For shared libraries that require a long time to load, this option is available so the library can be preloaded in the postmaster and inherited by all database sessions. </p></li><li class="listitem"><p> Improve optimizer cost computations, particularly for subqueries (Tom) </p></li><li class="listitem"><p> Avoid sort when subquery <code class="literal">ORDER BY</code> matches upper query (Tom) </p></li><li class="listitem"><p> Deduce that <code class="literal">WHERE a.x = b.y AND b.y = 42</code> also means <code class="literal">a.x = 42</code> (Tom) </p></li><li class="listitem"><p> Allow hash/merge joins on complex joins (Tom) </p></li><li class="listitem"><p> Allow hash joins for more data types (Tom) </p></li><li class="listitem"><p> Allow join optimization of explicit inner joins, disable with <code class="varname">join_collapse_limit</code> (Tom) </p></li><li class="listitem"><p> Add parameter <code class="varname">from_collapse_limit</code> to control conversion of subqueries to joins (Tom) </p></li><li class="listitem"><p> Use faster and more powerful regular expression code from Tcl (Henry Spencer, Tom) </p></li><li class="listitem"><p> Use bit-mapped relation sets in the optimizer (Tom) </p></li><li class="listitem"><p>Improve connection startup time (Tom)</p><p> The new client/server protocol requires fewer network packets to start a database session. </p></li><li class="listitem"><p> Improve trigger/constraint performance (Stephan) </p></li><li class="listitem"><p> Improve speed of <code class="literal">col IN (const, const, const, ...)</code> (Tom) </p></li><li class="listitem"><p> Fix hash indexes which were broken in rare cases (Tom) </p></li><li class="listitem"><p>Improve hash index concurrency and speed (Tom)</p><p> Prior releases suffered from poor hash index performance, particularly for high concurrency situations. This release fixes that, and the development group is interested in reports comparing B-tree and hash index performance. </p></li><li class="listitem"><p>Align shared buffers on 32-byte boundary for copy speed improvement (Manfred Spraul)</p><p> Certain CPU's perform faster data copies when addresses are 32-byte aligned. </p></li><li class="listitem"><p>Data type <code class="type">numeric</code> reimplemented for better performance (Tom)</p><p> <code class="type">numeric</code> used to be stored in base 100. The new code uses base 10000, for significantly better performance. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.5"><div class="titlepage"><div><div><h4 class="title">E.311.3.3. Server Configuration Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Rename server parameter <code class="varname">server_min_messages</code> to <code class="varname">log_min_messages</code> (Bruce)</p><p> This was done so most parameters that control the server logs begin with <code class="literal">log_</code>. </p></li><li class="listitem"><p>Rename <code class="varname">show_*_stats</code> to <code class="varname">log_*_stats</code> (Bruce)</p></li><li class="listitem"><p>Rename <code class="varname">show_source_port</code> to <code class="varname">log_source_port</code> (Bruce)</p></li><li class="listitem"><p>Rename <code class="varname">hostname_lookup</code> to <code class="varname">log_hostname</code> (Bruce)</p></li><li class="listitem"><p>Add <code class="varname">checkpoint_warning</code> to warn of excessive checkpointing (Bruce)</p><p> In prior releases, it was difficult to determine if checkpoint was happening too frequently. This feature adds a warning to the server logs when excessive checkpointing happens. </p></li><li class="listitem"><p>New read-only server parameters for localization (Tom)</p></li><li class="listitem"><p> Change debug server log messages to output as <code class="literal">DEBUG</code> rather than <code class="literal">LOG</code> (Bruce) </p></li><li class="listitem"><p>Prevent server log variables from being turned off by non-superusers (Bruce)</p><p> This is a security feature so non-superusers cannot disable logging that was enabled by the administrator. </p></li><li class="listitem"><p> <code class="varname">log_min_messages</code>/<code class="varname">client_min_messages</code> now controls <code class="varname">debug_*</code> output (Bruce) </p><p> This centralizes client debug information so all debug output can be sent to either the client or server logs. </p></li><li class="listitem"><p>Add macOS Rendezvous server support (Chris Campbell)</p><p> This allows macOS hosts to query the network for available <span class="productname">PostgreSQL</span> servers. </p></li><li class="listitem"><p> Add ability to print only slow statements using <code class="varname">log_min_duration_statement</code> (Christopher) </p><p> This is an often requested debugging feature that allows administrators to see only slow queries in their server logs. </p></li><li class="listitem"><p>Allow <code class="filename">pg_hba.conf</code> to accept netmasks in CIDR format (Andrew Dunstan)</p><p> This allows administrators to merge the host IP address and netmask fields into a single CIDR field in <code class="filename">pg_hba.conf</code>. </p></li><li class="listitem"><p>New read-only parameter <code class="varname">is_superuser</code> (Tom)</p></li><li class="listitem"><p>New parameter <code class="varname">log_error_verbosity</code> to control error detail (Tom)</p><p> This works with the new error reporting feature to supply additional error information like hints, file names and line numbers. </p></li><li class="listitem"><p><code class="literal">postgres --describe-config</code> now dumps server config variables (Aizaz Ahmed, Peter)</p><p> This option is useful for administration tools that need to know the configuration variable names and their minimums, maximums, defaults, and descriptions. </p></li><li class="listitem"><p> Add new columns in <code class="literal">pg_settings</code>: <code class="literal">context</code>, <code class="literal">type</code>, <code class="literal">source</code>, <code class="literal">min_val</code>, <code class="literal">max_val</code> (Joe) </p></li><li class="listitem"><p> Make default <code class="varname">shared_buffers</code> 1000 and <code class="varname">max_connections</code> 100, if possible (Tom) </p><p> Prior versions defaulted to 64 shared buffers so <span class="productname">PostgreSQL</span> would start on even very old systems. This release tests the amount of shared memory allowed by the platform and selects more reasonable default values if possible. Of course, users are still encouraged to evaluate their resource load and size <code class="varname">shared_buffers</code> accordingly. </p></li><li class="listitem"><p> New <code class="filename">pg_hba.conf</code> record type <code class="literal">hostnossl</code> to prevent SSL connections (Jon Jensen) </p><p> In prior releases, there was no way to prevent SSL connections if both the client and server supported SSL. This option allows that capability. </p></li><li class="listitem"><p> Remove parameter <code class="varname">geqo_random_seed</code> (Tom) </p></li><li class="listitem"><p> Add server parameter <code class="varname">regex_flavor</code> to control regular expression processing (Tom) </p></li><li class="listitem"><p> Make <code class="command">pg_ctl</code> better handle nonstandard ports (Greg) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.6"><div class="titlepage"><div><div><h4 class="title">E.311.3.4. Query Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>New SQL-standard information schema (Peter)</p></li><li class="listitem"><p>Add read-only transactions (Peter)</p></li><li class="listitem"><p>Print key name and value in foreign-key violation messages (Dmitry Tkach)</p></li><li class="listitem"><p>Allow users to see their own queries in <code class="literal">pg_stat_activity</code> (Kevin Brown)</p><p> In prior releases, only the superuser could see query strings using <code class="literal">pg_stat_activity</code>. Now ordinary users can see their own query strings. </p></li><li class="listitem"><p>Fix aggregates in subqueries to match SQL standard (Tom)</p><p> The SQL standard says that an aggregate function appearing within a nested subquery belongs to the outer query if its argument contains only outer-query variables. Prior <span class="productname">PostgreSQL</span> releases did not handle this fine point correctly. </p></li><li class="listitem"><p>Add option to prevent auto-addition of tables referenced in query (Nigel J. Andrews)</p><p> By default, tables mentioned in the query are automatically added to the <code class="literal">FROM</code> clause if they are not already there. This is compatible with historic <span class="productname">POSTGRES</span> behavior but is contrary to the SQL standard. This option allows selecting standard-compatible behavior. </p></li><li class="listitem"><p>Allow <code class="literal">UPDATE ... SET col = DEFAULT</code> (Rod)</p><p> This allows <code class="command">UPDATE</code> to set a column to its declared default value. </p></li><li class="listitem"><p>Allow expressions to be used in <code class="literal">LIMIT</code>/<code class="literal">OFFSET</code> (Tom)</p><p> In prior releases, <code class="literal">LIMIT</code>/<code class="literal">OFFSET</code> could only use constants, not expressions. </p></li><li class="listitem"><p>Implement <code class="literal">CREATE TABLE AS EXECUTE</code> (Neil, Peter)</p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.7"><div class="titlepage"><div><div><h4 class="title">E.311.3.5. Object Manipulation Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Make <code class="command">CREATE SEQUENCE</code> grammar more conforming to SQL:2003 (Neil)</p></li><li class="listitem"><p>Add statement-level triggers (Neil)</p><p> While this allows a trigger to fire at the end of a statement, it does not allow the trigger to access all rows modified by the statement. This capability is planned for a future release. </p></li><li class="listitem"><p>Add check constraints for domains (Rod)</p><p> This greatly increases the usefulness of domains by allowing them to use check constraints. </p></li><li class="listitem"><p>Add <code class="command">ALTER DOMAIN</code> (Rod)</p><p> This allows manipulation of existing domains. </p></li><li class="listitem"><p>Fix several zero-column table bugs (Tom)</p><p> <span class="productname">PostgreSQL</span> supports zero-column tables. This fixes various bugs that occur when using such tables. </p></li><li class="listitem"><p>Have <code class="literal">ALTER TABLE ... ADD PRIMARY KEY</code> add not-null constraint (Rod)</p><p> In prior releases, <code class="literal">ALTER TABLE ... ADD PRIMARY</code> would add a unique index, but not a not-null constraint. That is fixed in this release. </p></li><li class="listitem"><p>Add <code class="literal">ALTER TABLE ... WITHOUT OIDS</code> (Rod)</p><p> This allows control over whether new and updated rows will have an OID column. This is most useful for saving storage space. </p></li><li class="listitem"><p> Add <code class="literal">ALTER SEQUENCE</code> to modify minimum, maximum, increment, cache, cycle values (Rod) </p></li><li class="listitem"><p>Add <code class="literal">ALTER TABLE ... CLUSTER ON</code> (Alvaro Herrera)</p><p> This command is used by <code class="command">pg_dump</code> to record the cluster column for each table previously clustered. This information is used by database-wide cluster to cluster all previously clustered tables. </p></li><li class="listitem"><p>Improve automatic type casting for domains (Rod, Tom)</p></li><li class="listitem"><p>Allow dollar signs in identifiers, except as first character (Tom)</p></li><li class="listitem"><p>Disallow dollar signs in operator names, so <code class="literal">x=$1</code> works (Tom)</p></li><li class="listitem"><p> Allow copying table schema using <code class="literal">LIKE <em class="replaceable"><code>subtable</code></em></code>, also SQL:2003 feature <code class="literal">INCLUDING DEFAULTS</code> (Rod) </p></li><li class="listitem"><p> Add <code class="literal">WITH GRANT OPTION</code> clause to <code class="command">GRANT</code> (Peter) </p><p> This enabled <code class="command">GRANT</code> to give other users the ability to grant privileges on an object. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.8"><div class="titlepage"><div><div><h4 class="title">E.311.3.6. Utility Command Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Add <code class="literal">ON COMMIT</code> clause to <code class="command">CREATE TABLE</code> for temporary tables (Gavin)</p><p> This adds the ability for a table to be dropped or all rows deleted on transaction commit. </p></li><li class="listitem"><p>Allow cursors outside transactions using <code class="literal">WITH HOLD</code> (Neil)</p><p> In previous releases, cursors were removed at the end of the transaction that created them. Cursors can now be created with the <code class="literal">WITH HOLD</code> option, which allows them to continue to be accessed after the creating transaction has committed. </p></li><li class="listitem"><p><code class="literal">FETCH 0</code> and <code class="literal">MOVE 0 </code> now do nothing (Bruce)</p><p> In previous releases, <code class="literal">FETCH 0</code> fetched all remaining rows, and <code class="literal">MOVE 0</code> moved to the end of the cursor. </p></li><li class="listitem"><p> Cause <code class="command">FETCH</code> and <code class="command">MOVE</code> to return the number of rows fetched/moved, or zero if at the beginning/end of cursor, per SQL standard (Bruce) </p><p> In prior releases, the row count returned by <code class="command">FETCH</code> and <code class="command">MOVE</code> did not accurately reflect the number of rows processed. </p></li><li class="listitem"><p>Properly handle <code class="literal">SCROLL</code> with cursors, or report an error (Neil)</p><p> Allowing random access (both forward and backward scrolling) to some kinds of queries cannot be done without some additional work. If <code class="literal">SCROLL</code> is specified when the cursor is created, this additional work will be performed. Furthermore, if the cursor has been created with <code class="literal">NO SCROLL</code>, no random access is allowed. </p></li><li class="listitem"><p> Implement SQL-compatible options <code class="literal">FIRST</code>, <code class="literal">LAST</code>, <code class="literal">ABSOLUTE <em class="replaceable"><code>n</code></em></code>, <code class="literal">RELATIVE <em class="replaceable"><code>n</code></em></code> for <code class="command">FETCH</code> and <code class="command">MOVE</code> (Tom) </p></li><li class="listitem"><p>Allow <code class="command">EXPLAIN</code> on <code class="command">DECLARE CURSOR</code> (Tom)</p></li><li class="listitem"><p>Allow <code class="command">CLUSTER</code> to use index marked as pre-clustered by default (Alvaro Herrera)</p></li><li class="listitem"><p>Allow <code class="command">CLUSTER</code> to cluster all tables (Alvaro Herrera)</p><p> This allows all previously clustered tables in a database to be reclustered with a single command. </p></li><li class="listitem"><p>Prevent <code class="command">CLUSTER</code> on partial indexes (Tom)</p></li><li class="listitem"><p>Allow DOS and Mac line-endings in <code class="command">COPY</code> files (Bruce)</p></li><li class="listitem"><p> Disallow literal carriage return as a data value, backslash-carriage-return and <code class="literal">\r</code> are still allowed (Bruce) </p></li><li class="listitem"><p><code class="command">COPY</code> changes (binary, <code class="literal">\.</code>) (Tom)</p></li><li class="listitem"><p>Recover from <code class="command">COPY</code> failure cleanly (Tom)</p></li><li class="listitem"><p>Prevent possible memory leaks in <code class="command">COPY</code> (Tom)</p></li><li class="listitem"><p>Make <code class="command">TRUNCATE</code> transaction-safe (Rod)</p><p> <code class="command">TRUNCATE</code> can now be used inside a transaction. If the transaction aborts, the changes made by the <code class="command">TRUNCATE</code> are automatically rolled back. </p></li><li class="listitem"><p> Allow prepare/bind of utility commands like <code class="command">FETCH</code> and <code class="command">EXPLAIN</code> (Tom) </p></li><li class="listitem"><p>Add <code class="command">EXPLAIN EXECUTE</code> (Neil)</p></li><li class="listitem"><p>Improve <code class="command">VACUUM</code> performance on indexes by reducing WAL traffic (Tom)</p></li><li class="listitem"><p>Functional indexes have been generalized into indexes on expressions (Tom)</p><p> In prior releases, functional indexes only supported a simple function applied to one or more column names. This release allows any type of scalar expression. </p></li><li class="listitem"><p> Have <code class="command">SHOW TRANSACTION ISOLATION</code> match input to <code class="command">SET TRANSACTION ISOLATION</code> (Tom) </p></li><li class="listitem"><p> Have <code class="command">COMMENT ON DATABASE</code> on nonlocal database generate a warning, rather than an error (Rod) </p><p> Database comments are stored in database-local tables so comments on a database have to be stored in each database. </p></li><li class="listitem"><p> Improve reliability of <code class="command">LISTEN</code>/<code class="command">NOTIFY</code> (Tom) </p></li><li class="listitem"><p>Allow <code class="command">REINDEX</code> to reliably reindex nonshared system catalog indexes (Tom)</p><p> This allows system tables to be reindexed without the requirement of a standalone session, which was necessary in previous releases. The only tables that now require a standalone session for reindexing are the global system tables <code class="literal">pg_database</code>, <code class="literal">pg_shadow</code>, and <code class="literal">pg_group</code>. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.9"><div class="titlepage"><div><div><h4 class="title">E.311.3.7. Data Type and Function Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> New server parameter <code class="varname">extra_float_digits</code> to control precision display of floating-point numbers (Pedro Ferreira, Tom) </p><p> This controls output precision which was causing regression testing problems. </p></li><li class="listitem"><p>Allow <code class="literal">+1300</code> as a numeric time-zone specifier, for FJST (Tom)</p></li><li class="listitem"><p> Remove rarely used functions <code class="function">oidrand</code>, <code class="function">oidsrand</code>, and <code class="function">userfntest</code> functions (Neil) </p></li><li class="listitem"><p>Add <code class="function">md5()</code> function to main server, already in <code class="filename">contrib/pgcrypto</code> (Joe)</p><p> An MD5 function was frequently requested. For more complex encryption capabilities, use <code class="filename">contrib/pgcrypto</code>. </p></li><li class="listitem"><p>Increase date range of <code class="type">timestamp</code> (John Cochran)</p></li><li class="listitem"><p> Change <code class="literal">EXTRACT(EPOCH FROM timestamp)</code> so <code class="type">timestamp without time zone</code> is assumed to be in local time, not GMT (Tom) </p></li><li class="listitem"><p>Trap division by zero in case the operating system doesn't prevent it (Tom)</p></li><li class="listitem"><p>Change the <code class="type">numeric</code> data type internally to base 10000 (Tom)</p></li><li class="listitem"><p>New <code class="function">hostmask()</code> function (Greg Wickham)</p></li><li class="listitem"><p>Fixes for <code class="function">to_char()</code> and <code class="function">to_timestamp()</code> (Karel)</p></li><li class="listitem"><p> Allow functions that can take any argument data type and return any data type, using <code class="type">anyelement</code> and <code class="type">anyarray</code> (Joe) </p><p> This allows the creation of functions that can work with any data type. </p></li><li class="listitem"><p> Arrays can now be specified as <code class="literal">ARRAY[1,2,3]</code>, <code class="literal">ARRAY[['a','b'],['c','d']]</code>, or <code class="literal">ARRAY[ARRAY[ARRAY[2]]]</code> (Joe) </p></li><li class="listitem"><p> Allow proper comparisons for arrays, including <code class="literal">ORDER BY</code> and <code class="literal">DISTINCT</code> support (Joe) </p></li><li class="listitem"><p>Allow indexes on array columns (Joe)</p></li><li class="listitem"><p>Allow array concatenation with <code class="literal">||</code> (Joe)</p></li><li class="listitem"><p> Allow <code class="literal">WHERE</code> qualification <code class="literal"><em class="replaceable"><code>expr</code></em> <em class="replaceable"><code>op</code></em> ANY/SOME/ALL (<em class="replaceable"><code>array_expr</code></em>)</code> (Joe) </p><p> This allows arrays to behave like a list of values, for purposes like <code class="literal">SELECT * FROM tab WHERE col IN (array_val)</code>. </p></li><li class="listitem"><p> New array functions <code class="function">array_append</code>, <code class="function">array_cat</code>, <code class="function">array_lower</code>, <code class="function">array_prepend</code>, <code class="function">array_to_string</code>, <code class="function">array_upper</code>, <code class="function">string_to_array</code> (Joe) </p></li><li class="listitem"><p>Allow user defined aggregates to use polymorphic functions (Joe)</p></li><li class="listitem"><p>Allow assignments to empty arrays (Joe)</p></li><li class="listitem"><p> Allow 60 in seconds fields of <code class="type">time</code>, <code class="type">timestamp</code>, and <code class="type">interval</code> input values (Tom) </p><p> Sixty-second values are needed for leap seconds. </p></li><li class="listitem"><p>Allow <code class="type">cidr</code> data type to be cast to <code class="type">text</code> (Tom)</p></li><li class="listitem"><p>Disallow invalid time zone names in SET TIMEZONE</p></li><li class="listitem"><p> Trim trailing spaces when <code class="type">char</code> is cast to <code class="type">varchar</code> or <code class="type">text</code> (Tom) </p></li><li class="listitem"><p> Make <code class="type">float(<em class="replaceable"><code>p</code></em>)</code> measure the precision <em class="replaceable"><code>p</code></em> in binary digits, not decimal digits (Tom) </p></li><li class="listitem"><p>Add IPv6 support to the <code class="type">inet</code> and <code class="type">cidr</code> data types (Michael Graff)</p></li><li class="listitem"><p>Add <code class="function">family()</code> function to report whether address is IPv4 or IPv6 (Michael Graff)</p></li><li class="listitem"><p> Have <code class="literal">SHOW datestyle</code> generate output similar to that used by <code class="literal">SET datestyle</code> (Tom) </p></li><li class="listitem"><p> Make <code class="literal">EXTRACT(TIMEZONE)</code> and <code class="literal">SET/SHOW TIME ZONE</code> follow the SQL convention for the sign of time zone offsets, i.e., positive is east from UTC (Tom) </p></li><li class="listitem"><p>Fix <code class="literal">date_trunc('quarter', ...)</code> (Böjthe Zoltán)</p><p> Prior releases returned an incorrect value for this function call. </p></li><li class="listitem"><p>Make <code class="function">initcap()</code> more compatible with Oracle (Mike Nolan)</p><p> <code class="function">initcap()</code> now uppercases a letter appearing after any non-alphanumeric character, rather than only after whitespace. </p></li><li class="listitem"><p>Allow only <code class="varname">datestyle</code> field order for date values not in ISO-8601 format (Greg)</p></li><li class="listitem"><p> Add new <code class="varname">datestyle</code> values <code class="literal">MDY</code>, <code class="literal">DMY</code>, and <code class="literal">YMD</code> to set input field order; honor <code class="literal">US</code> and <code class="literal">European</code> for backward compatibility (Tom) </p></li><li class="listitem"><p> String literals like <code class="literal">'now'</code> or <code class="literal">'today'</code> will no longer work as a column default. Use functions such as <code class="function">now()</code>, <code class="function">current_timestamp</code> instead. (change required for prepared statements) (Tom) </p></li><li class="listitem"><p>Treat NaN as larger than any other value in <code class="function">min()</code>/<code class="function">max()</code> (Tom)</p><p> NaN was already sorted after ordinary numeric values for most purposes, but <code class="function">min()</code> and <code class="function">max()</code> didn't get this right. </p></li><li class="listitem"><p>Prevent interval from suppressing <code class="literal">:00</code> seconds display</p></li><li class="listitem"><p> New functions <code class="function">pg_get_triggerdef(prettyprint)</code> and <code class="function">pg_conversion_is_visible()</code> (Christopher) </p></li><li class="listitem"><p>Allow time to be specified as <code class="literal">040506</code> or <code class="literal">0405</code> (Tom)</p></li><li class="listitem"><p> Input date order must now be <code class="literal">YYYY-MM-DD</code> (with 4-digit year) or match <code class="varname">datestyle</code> </p></li><li class="listitem"><p> Make <code class="function">pg_get_constraintdef</code> support unique, primary-key, and check constraints (Christopher) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.10"><div class="titlepage"><div><div><h4 class="title">E.311.3.8. Server-Side Language Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Prevent PL/pgSQL crash when <code class="literal">RETURN NEXT</code> is used on a zero-row record variable (Tom) </p></li><li class="listitem"><p> Make PL/Python's <code class="function">spi_execute</code> interface handle null values properly (Andrew Bosma) </p></li><li class="listitem"><p>Allow PL/pgSQL to declare variables of composite types without <code class="literal">%ROWTYPE</code> (Tom)</p></li><li class="listitem"><p>Fix PL/Python's <code class="function">_quote()</code> function to handle big integers</p></li><li class="listitem"><p>Make PL/Python an untrusted language, now called <code class="literal">plpythonu</code> (Kevin Jacobs, Tom)</p><p> The Python language no longer supports a restricted execution environment, so the trusted version of PL/Python was removed. If this situation changes, a version of PL/Python that can be used by non-superusers will be readded. </p></li><li class="listitem"><p>Allow polymorphic PL/pgSQL functions (Joe, Tom)</p></li><li class="listitem"><p>Allow polymorphic SQL functions (Joe)</p></li><li class="listitem"><p> Improved compiled function caching mechanism in PL/pgSQL with full support for polymorphism (Joe) </p></li><li class="listitem"><p> Add new parameter <code class="literal">$0</code> in PL/pgSQL representing the function's actual return type (Joe) </p></li><li class="listitem"><p> Allow PL/Tcl and PL/Python to use the same trigger on multiple tables (Tom) </p></li><li class="listitem"><p> Fixed PL/Tcl's <code class="function">spi_prepare</code> to accept fully qualified type names in the parameter type list (Jan) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.11"><div class="titlepage"><div><div><h4 class="title">E.311.3.9. psql Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Add <code class="literal">\pset pager always</code> to always use pager (Greg)</p><p> This forces the pager to be used even if the number of rows is less than the screen height. This is valuable for rows that wrap across several screen rows. </p></li><li class="listitem"><p>Improve tab completion (Rod, Ross Reedstrom, Ian Barwick)</p></li><li class="listitem"><p>Reorder <code class="literal">\?</code> help into groupings (Harald Armin Massa, Bruce)</p></li><li class="listitem"><p>Add backslash commands for listing schemas, casts, and conversions (Christopher)</p></li><li class="listitem"><p> <code class="command">\encoding</code> now changes based on the server parameter <code class="varname">client_encoding</code> (Tom) </p><p> In previous versions, <code class="command">\encoding</code> was not aware of encoding changes made using <code class="literal">SET client_encoding</code>. </p></li><li class="listitem"><p>Save editor buffer into readline history (Ross)</p><p> When <code class="command">\e</code> is used to edit a query, the result is saved in the readline history for retrieval using the up arrow. </p></li><li class="listitem"><p>Improve <code class="command">\d</code> display (Christopher)</p></li><li class="listitem"><p>Enhance HTML mode to be more standards-conforming (Greg)</p></li><li class="listitem"><p>New <code class="command">\set AUTOCOMMIT off</code> capability (Tom)</p><p> This takes the place of the removed server parameter <code class="varname">autocommit</code>. </p></li><li class="listitem"><p>New <code class="command">\set VERBOSITY</code> to control error detail (Tom)</p><p> This controls the new error reporting details. </p></li><li class="listitem"><p>New prompt escape sequence <code class="literal">%x</code> to show transaction status (Tom)</p></li><li class="listitem"><p>Long options for <span class="application">psql</span> are now available on all platforms</p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.12"><div class="titlepage"><div><div><h4 class="title">E.311.3.10. pg_dump Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Multiple pg_dump fixes, including tar format and large objects</p></li><li class="listitem"><p>Allow pg_dump to dump specific schemas (Neil)</p></li><li class="listitem"><p>Make pg_dump preserve column storage characteristics (Christopher)</p><p> This preserves <code class="literal">ALTER TABLE ... SET STORAGE</code> information. </p></li><li class="listitem"><p>Make pg_dump preserve <code class="command">CLUSTER</code> characteristics (Christopher)</p></li><li class="listitem"><p> Have pg_dumpall use <code class="command">GRANT</code>/<code class="command">REVOKE</code> to dump database-level privileges (Tom) </p></li><li class="listitem"><p> Allow pg_dumpall to support the options <code class="option">-a</code>, <code class="option">-s</code>, <code class="option">-x</code> of pg_dump (Tom) </p></li><li class="listitem"><p>Prevent pg_dump from lowercasing identifiers specified on the command line (Tom)</p></li><li class="listitem"><p> pg_dump options <code class="option">--use-set-session-authorization</code> and <code class="option">--no-reconnect</code> now do nothing, all dumps use <code class="command">SET SESSION AUTHORIZATION</code> </p><p> pg_dump no longer reconnects to switch users, but instead always uses <code class="command">SET SESSION AUTHORIZATION</code>. This will reduce password prompting during restores. </p></li><li class="listitem"><p>Long options for <span class="application">pg_dump</span> are now available on all platforms</p><p> <span class="productname">PostgreSQL</span> now includes its own long-option processing routines. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.13"><div class="titlepage"><div><div><h4 class="title">E.311.3.11. libpq Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> Add function <code class="function">PQfreemem</code> for freeing memory on Windows, suggested for <code class="command">NOTIFY</code> (Bruce) </p><p> Windows requires that memory allocated in a library be freed by a function in the same library, hence <code class="function">free()</code> doesn't work for freeing memory allocated by libpq. <code class="function">PQfreemem</code> is the proper way to free libpq memory, especially on Windows, and is recommended for other platforms as well. </p></li><li class="listitem"><p>Document service capability, and add sample file (Bruce)</p><p> This allows clients to look up connection information in a central file on the client machine. </p></li><li class="listitem"><p> Make <code class="function">PQsetdbLogin</code> have the same defaults as <code class="function">PQconnectdb</code> (Tom) </p></li><li class="listitem"><p>Allow libpq to cleanly fail when result sets are too large (Tom)</p></li><li class="listitem"><p> Improve performance of function <code class="function">PQunescapeBytea</code> (Ben Lamb) </p></li><li class="listitem"><p> Allow thread-safe libpq with <code class="filename">configure</code> option <code class="option">--enable-thread-safety</code> (Lee Kindness, Philip Yarra) </p></li><li class="listitem"><p> Allow function <code class="function">pqInternalNotice</code> to accept a format string and arguments instead of just a preformatted message (Tom, Sean Chittenden) </p></li><li class="listitem"><p> Control SSL negotiation with <code class="literal">sslmode</code> values <code class="literal">disable</code>, <code class="literal">allow</code>, <code class="literal">prefer</code>, and <code class="literal">require</code> (Jon Jensen) </p></li><li class="listitem"><p>Allow new error codes and levels of text (Tom)</p></li><li class="listitem"><p>Allow access to the underlying table and column of a query result (Tom)</p><p> This is helpful for query-builder applications that want to know the underlying table and column names associated with a specific result set. </p></li><li class="listitem"><p>Allow access to the current transaction status (Tom)</p></li><li class="listitem"><p>Add ability to pass binary data directly to the server (Tom)</p></li><li class="listitem"><p> Add function <code class="function">PQexecPrepared</code> and <code class="function">PQsendQueryPrepared</code> functions which perform bind/execute of previously prepared statements (Tom) </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.14"><div class="titlepage"><div><div><h4 class="title">E.311.3.12. JDBC Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Allow <code class="function">setNull</code> on updateable result sets</p></li><li class="listitem"><p>Allow <code class="function">executeBatch</code> on a prepared statement (Barry)</p></li><li class="listitem"><p>Support SSL connections (Barry)</p></li><li class="listitem"><p>Handle schema names in result sets (Paul Sorenson)</p></li><li class="listitem"><p>Add refcursor support (Nic Ferrier)</p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.15"><div class="titlepage"><div><div><h4 class="title">E.311.3.13. Miscellaneous Interface Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Prevent possible memory leak or core dump during libpgtcl shutdown (Tom)</p></li><li class="listitem"><p>Add Informix compatibility to ECPG (Michael)</p><p> This allows ECPG to process embedded C programs that were written using certain Informix extensions. </p></li><li class="listitem"><p>Add type <code class="type">decimal</code> to ECPG that is fixed length, for Informix (Michael)</p></li><li class="listitem"><p> Allow thread-safe embedded SQL programs with <code class="filename">configure</code> option <code class="option">--enable-thread-safety</code> (Lee Kindness, Bruce) </p><p> This allows multiple threads to access the database at the same time. </p></li><li class="listitem"><p>Moved Python client PyGreSQL to <a class="ulink" href="http://www.pygresql.org" target="_top">http://www.pygresql.org</a> (Marc)</p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.16"><div class="titlepage"><div><div><h4 class="title">E.311.3.14. Source Code Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Prevent need for separate platform geometry regression result files (Tom)</p></li><li class="listitem"><p>Improved PPC locking primitive (Reinhard Max)</p></li><li class="listitem"><p>New function <code class="function">palloc0</code> to allocate and clear memory (Bruce)</p></li><li class="listitem"><p>Fix locking code for s390x CPU (64-bit) (Tom)</p></li><li class="listitem"><p>Allow OpenBSD to use local ident credentials (William Ahern)</p></li><li class="listitem"><p>Make query plan trees read-only to executor (Tom)</p></li><li class="listitem"><p>Add macOS startup scripts (David Wheeler)</p></li><li class="listitem"><p>Allow libpq to compile with Borland C++ compiler (Lester Godwin, Karl Waclawek)</p></li><li class="listitem"><p>Use our own version of <code class="function">getopt_long()</code> if needed (Peter)</p></li><li class="listitem"><p>Convert administration scripts to C (Peter)</p></li><li class="listitem"><p> Bison >= 1.85 is now required to build the <span class="productname">PostgreSQL</span> grammar, if building from CVS</p></li><li class="listitem"><p>Merge documentation into one book (Peter)</p></li><li class="listitem"><p>Add Windows compatibility functions (Bruce)</p></li><li class="listitem"><p>Allow client interfaces to compile under MinGW (Bruce)</p></li><li class="listitem"><p>New <code class="function">ereport()</code> function for error reporting (Tom)</p></li><li class="listitem"><p>Support Intel compiler on Linux (Peter)</p></li><li class="listitem"><p>Improve Linux startup scripts (Slawomir Sudnik, Darko Prenosil)</p></li><li class="listitem"><p>Add support for AMD Opteron and Itanium (Jeffrey W. Baker, Bruce)</p></li><li class="listitem"><p>Remove <code class="option">--enable-recode</code> option from <code class="command">configure</code></p><p> This was no longer needed now that we have <code class="command">CREATE CONVERSION</code>. </p></li><li class="listitem"><p>Generate a compile error if spinlock code is not found (Bruce)</p><p> Platforms without spinlock code will now fail to compile, rather than silently using semaphores. This failure can be disabled with a new <code class="command">configure</code> option. </p></li></ul></div></div><div class="sect3" id="id-1.11.6.315.5.17"><div class="titlepage"><div><div><h4 class="title">E.311.3.15. Contrib Changes</h4></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>Change dbmirror license to BSD</p></li><li class="listitem"><p>Improve earthdistance (Bruno Wolff III)</p></li><li class="listitem"><p>Portability improvements to pgcrypto (Marko Kreen)</p></li><li class="listitem"><p>Prevent crash in xml (John Gray, Michael Richards)</p></li><li class="listitem"><p>Update oracle</p></li><li class="listitem"><p>Update mysql</p></li><li class="listitem"><p>Update cube (Bruno Wolff III)</p></li><li class="listitem"><p>Update earthdistance to use cube (Bruno Wolff III)</p></li><li class="listitem"><p>Update btree_gist (Oleg)</p></li><li class="listitem"><p>New tsearch2 full-text search module (Oleg, Teodor)</p></li><li class="listitem"><p>Add hash-based crosstab function to tablefuncs (Joe)</p></li><li class="listitem"><p>Add serial column to order <code class="function">connectby()</code> siblings in tablefuncs (Nabil Sayegh,Joe)</p></li><li class="listitem"><p>Add named persistent connections to dblink (Shridhar Daithanka)</p></li><li class="listitem"><p>New pg_autovacuum allows automatic <code class="command">VACUUM</code> (Matthew T. O'Connor)</p></li><li class="listitem"><p>Make pgbench honor environment variables <code class="envar">PGHOST</code>, <code class="envar">PGPORT</code>, <code class="envar">PGUSER</code> (Tatsuo)</p></li><li class="listitem"><p>Improve intarray (Teodor Sigaev)</p></li><li class="listitem"><p>Improve pgstattuple (Rod)</p></li><li class="listitem"><p>Fix bug in <code class="function">metaphone()</code> in fuzzystrmatch</p></li><li class="listitem"><p>Improve adddepend (Rod)</p></li><li class="listitem"><p>Update spi/timetravel (Böjthe Zoltán)</p></li><li class="listitem"><p>Fix dbase <code class="option">-s</code> option and improve non-ASCII handling (Thomas Behr, Márcio Smiderle)</p></li><li class="listitem"><p>Remove array module because features now included by default (Joe)</p></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-7-4-1.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-7-3-21.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">E.310. 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