{ \ echo ""; \ echo ""; \ } > version.sgml '/usr/bin/perl' ./mk_feature_tables.pl YES ../../../src/backend/catalog/sql_feature_packages.txt ../../../src/backend/catalog/sql_features.txt > features-supported.sgml '/usr/bin/perl' ./mk_feature_tables.pl NO ../../../src/backend/catalog/sql_feature_packages.txt ../../../src/backend/catalog/sql_features.txt > features-unsupported.sgml '/usr/bin/perl' ./generate-errcodes-table.pl ../../../src/backend/utils/errcodes.txt > errcodes-table.sgml jade -wall -wno-unused-param -wno-empty -wfully-tagged -D . -D . -d stylesheet.dsl -t sgml -i output-html -V html-index postgres.sgml jade:E: unknown warning type "fully-tagged" jade:postgres.sgml:3:55:W: cannot generate system identifier for public text "-//OASIS//DTD DocBook V4.2//EN" jade:postgres.sgml:12:0:E: reference to entity "BOOK" for which no system identifier could be generated jade:postgres.sgml:3:0: entity was defined here jade:postgres.sgml:12:0:E: DTD did not contain element declaration for document type name jade:postgres.sgml:14:9:E: there is no attribute "ID" jade:postgres.sgml:14:19:E: element "BOOK" undefined jade:postgres.sgml:15:7:E: element "TITLE" undefined jade:postgres.sgml:17:10:E: element "BOOKINFO" undefined jade:postgres.sgml:18:13:E: element "CORPAUTHOR" undefined jade:postgres.sgml:19:14:E: element "PRODUCTNAME" undefined jade:postgres.sgml:20:16:E: element "PRODUCTNUMBER" undefined jade:legal.sgml:3:5:E: element "DATE" undefined jade:legal.sgml:5:10:E: element "COPYRIGHT" undefined jade:legal.sgml:6:6:E: element "YEAR" undefined jade:legal.sgml:7:8:E: element "HOLDER" undefined jade:legal.sgml:10:16:E: there is no attribute "ID" jade:legal.sgml:10:29:E: element "LEGALNOTICE" undefined jade:legal.sgml:11:7:E: element "TITLE" undefined jade:legal.sgml:13:6:E: element "PARA" undefined jade:legal.sgml:14:14:E: element "PRODUCTNAME" undefined jade:legal.sgml:14:54:E: general entity "copy" not defined and no default entity jade:legal.sgml:18:6:E: element "PARA" undefined jade:legal.sgml:19:14:E: element "PRODUCTNAME" undefined jade:legal.sgml:23:6:E: element "PARA" undefined jade:legal.sgml:31:6:E: element "PARA" undefined jade:legal.sgml:39:6:E: element "PARA" undefined jade:legal.sgml:43:36:E: element "QUOTE" undefined jade:intro.sgml:3:12:E: there is no attribute "ID" jade:intro.sgml:3:21:E: element "PREFACE" undefined jade:intro.sgml:4:7:E: element "TITLE" undefined jade:intro.sgml:6:6:E: element "PARA" undefined jade:intro.sgml:8:14:E: element "PRODUCTNAME" undefined jade:intro.sgml:9:14:E: element "PRODUCTNAME" undefined jade:intro.sgml:11:14:E: element "PRODUCTNAME" undefined jade:intro.sgml:13:14:E: element "PRODUCTNAME" undefined jade:intro.sgml:16:6:E: element "PARA" undefined jade:intro.sgml:18:14:E: element "PRODUCTNAME" undefined jade:intro.sgml:21:14:E: element "PRODUCTNAME" undefined jade:intro.sgml:23:15:E: element "ITEMIZEDLIST" undefined jade:intro.sgml:24:12:E: element "LISTITEM" undefined jade:intro.sgml:25:9:E: element "PARA" undefined jade:intro.sgml:26:19:E: there is no attribute "LINKEND" jade:intro.sgml:26:29:E: element "XREF" undefined jade:intro.sgml:27:10:E: end tag for "XREF" omitted, but its declaration does not permit this jade:intro.sgml:26:5: start tag was here jade:intro.sgml:30:12:E: element "LISTITEM" undefined jade:intro.sgml:31:9:E: element "PARA" undefined jade:intro.sgml:32:24:E: element "XREF" undefined jade:intro.sgml:32:48:E: element "ACRONYM" undefined jade:intro.sgml:35:17:E: element "PRODUCTNAME" undefined jade:intro.sgml:36:10:E: end tag for "XREF" omitted, but its declaration does not permit this jade:intro.sgml:32:5: start tag was here jade:intro.sgml:39:12:E: element "LISTITEM" undefined jade:intro.sgml:40:9:E: element "PARA" undefined jade:intro.sgml:41:26:E: element "XREF" undefined jade:intro.sgml:43:17:E: element "PRODUCTNAME" undefined jade:intro.sgml:45:10:E: end tag for "XREF" omitted, but its declaration does not permit this jade:intro.sgml:41:5: start tag was here jade:intro.sgml:48:12:E: element "LISTITEM" undefined jade:intro.sgml:49:9:E: element "PARA" undefined jade:intro.sgml:50:38:E: element "XREF" undefined jade:intro.sgml:51:32:E: element "PRODUCTNAME" undefined jade:intro.sgml:53:10:E: end tag for "XREF" omitted, but its declaration does not permit this jade:intro.sgml:50:5: start tag was here jade:intro.sgml:57:12:E: element "LISTITEM" undefined jade:intro.sgml:58:9:E: element "PARA" undefined jade:intro.sgml:59:39:E: element "XREF" undefined jade:intro.sgml:63:10:E: end tag for "XREF" omitted, but its declaration does not permit this jade:intro.sgml:59:5: start tag was here jade:intro.sgml:66:12:E: element "LISTITEM" undefined jade:intro.sgml:67:9:E: element "PARA" undefined jade:intro.sgml:68:30:E: element "XREF" undefined jade:intro.sgml:72:10:E: end tag for "XREF" omitted, but its declaration does not permit this jade:intro.sgml:68:5: start tag was here jade:intro.sgml:75:12:E: element "LISTITEM" undefined jade:intro.sgml:76:9:E: element "PARA" undefined jade:intro.sgml:77:30:E: element "XREF" undefined jade:intro.sgml:78:24:E: element "PRODUCTNAME" undefined jade:intro.sgml:79:10:E: end tag for "XREF" omitted, but its declaration does not permit this jade:intro.sgml:77:5: start tag was here jade:intro.sgml:84:11:E: there is no attribute "ID" jade:intro.sgml:84:25:E: element "SECT1" undefined jade:intro.sgml:85:8:E: element "TITLE" undefined jade:intro.sgml:85:30:E: element "PRODUCTNAME" undefined jade:intro.sgml:87:7:E: element "PARA" undefined jade:intro.sgml:88:15:E: element "PRODUCTNAME" undefined jade:intro.sgml:89:39:E: element "ACRONYM" undefined jade:intro.sgml:90:14:E: there is no attribute "URL" jade:intro.sgml:90:55:E: element "ULINK" undefined jade:intro.sgml:91:15:E: element "PRODUCTNAME" undefined jade:intro.sgml:97:7:E: element "PARA" undefined jade:intro.sgml:98:15:E: element "PRODUCTNAME" undefined jade:intro.sgml:102:25:E: there is no attribute "SPACING" jade:intro.sgml:102:34:E: element "ITEMIZEDLIST" undefined jade:intro.sgml:103:13:E: element "LISTITEM" undefined jade:intro.sgml:104:13:E: element "SIMPARA" undefined jade:intro.sgml:106:13:E: element "LISTITEM" undefined jade:intro.sgml:107:13:E: element "SIMPARA" undefined jade:intro.sgml:109:13:E: element "LISTITEM" undefined jade:intro.sgml:110:13:E: element "SIMPARA" undefined jade:intro.sgml:112:13:E: element "LISTITEM" undefined jade:intro.sgml:113:13:E: element "SIMPARA" undefined jade:intro.sgml:115:13:E: element "LISTITEM" undefined jade:intro.sgml:116:13:E: element "SIMPARA" undefined jade:intro.sgml:118:13:E: element "LISTITEM" undefined jade:intro.sgml:119:13:E: element "SIMPARA" undefined jade:intro.sgml:123:21:E: element "PRODUCTNAME" undefined jade:intro.sgml:126:34:E: element "ITEMIZEDLIST" undefined jade:intro.sgml:127:13:E: element "LISTITEM" undefined jade:intro.sgml:128:13:E: element "SIMPARA" undefined jade:intro.sgml:130:13:E: element "LISTITEM" undefined jade:intro.sgml:131:13:E: element "SIMPARA" undefined jade:intro.sgml:133:13:E: element "LISTITEM" undefined jade:intro.sgml:134:13:E: element "SIMPARA" undefined jade:intro.sgml:136:13:E: element "LISTITEM" undefined jade:intro.sgml:137:13:E: element "SIMPARA" undefined jade:intro.sgml:139:13:E: element "LISTITEM" undefined jade:intro.sgml:140:13:E: element "SIMPARA" undefined jade:intro.sgml:142:13:E: element "LISTITEM" undefined jade:intro.sgml:143:13:E: element "SIMPARA" undefined jade:intro.sgml:148:7:E: element "PARA" undefined jade:intro.sgml:150:15:E: element "PRODUCTNAME" undefined jade:history.sgml:3:19:E: element "SECT1" undefined jade:history.sgml:4:7:E: element "TITLE" undefined jade:history.sgml:4:39:E: element "PRODUCTNAME" undefined jade:history.sgml:6:17:E: there is no attribute "ZONE" jade:history.sgml:6:26:E: element "INDEXTERM" undefined jade:history.sgml:7:10:E: element "PRIMARY" undefined jade:history.sgml:8:12:E: element "SECONDARY" undefined jade:history.sgml:11:6:E: element "PARA" undefined jade:history.sgml:13:14:E: element "PRODUCTNAME" undefined jade:history.sgml:14:14:E: element "PRODUCTNAME" undefined jade:history.sgml:16:37:E: element "PRODUCTNAME" undefined jade:history.sgml:20:11:E: there is no attribute "ID" jade:history.sgml:20:29:E: element "SECT2" undefined jade:history.sgml:21:8:E: element "TITLE" undefined jade:history.sgml:21:34:E: element "PRODUCTNAME" undefined jade:history.sgml:23:36:E: element "INDEXTERM" undefined jade:history.sgml:24:11:E: element "PRIMARY" undefined jade:history.sgml:27:7:E: element "PARA" undefined jade:history.sgml:28:19:E: element "PRODUCTNAME" undefined jade:history.sgml:30:28:E: element "ACRONYM" undefined jade:history.sgml:31:19:E: element "ACRONYM" undefined jade:history.sgml:32:12:E: element "ACRONYM" undefined jade:history.sgml:33:15:E: element "PRODUCTNAME" undefined jade:history.sgml:34:67:E: element "XREF" undefined jade:history.sgml:36:19:E: element "XREF" undefined jade:history.sgml:37:39:E: element "XREF" undefined jade:history.sgml:39:20:E: element "XREF" undefined jade:history.sgml:40:8:E: end tag for "XREF" omitted, but its declaration does not permit this jade:history.sgml:38:56: start tag was here jade:history.sgml:40:8:E: end tag for "XREF" omitted, but its declaration does not permit this jade:history.sgml:37:16: start tag was here jade:history.sgml:40:8:E: end tag for "XREF" omitted, but its declaration does not permit this jade:history.sgml:35:60: start tag was here jade:history.sgml:40:8:E: end tag for "XREF" omitted, but its declaration does not permit this jade:history.sgml:34:45: start tag was here jade:history.sgml:42:7:E: element "PARA" undefined jade:history.sgml:43:15:E: element "PRODUCTNAME" undefined jade:history.sgml:44:41:E: element "QUOTE" undefined jade:history.sgml:46:11:E: element "ACRONYM" undefined jade:history.sgml:47:26:E: element "XREF" undefined jade:history.sgml:49:26:E: element "XREF" undefined jade:history.sgml:50:20:E: element "XREF" undefined jade:history.sgml:54:21:E: element "PRODUCTNAME" undefined jade:history.sgml:56:8:E: end tag for "XREF" omitted, but its declaration does not permit this jade:history.sgml:49:62: start tag was here jade:history.sgml:56:8:E: end tag for "XREF" omitted, but its declaration does not permit this jade:history.sgml:49:4: start tag was here jade:history.sgml:56:8:E: end tag for "XREF" omitted, but its declaration does not permit this jade:history.sgml:47:3: start tag was here jade:history.sgml:58:7:E: element "PARA" undefined jade:history.sgml:59:15:E: element "PRODUCTNAME" undefined jade:history.sgml:64:15:E: element "PRODUCTNAME" undefined jade:history.sgml:67:40:E: element "ULINK" undefined jade:history.sgml:67:53:E: element "PRODUCTNAME" undefined jade:history.sgml:69:28:E: element "ULINK" undefined jade:history.sgml:71:15:E: element "PRODUCTNAME" undefined jade:history.sgml:73:57:E: element "ULINK" undefined jade:history.sgml:77:7:E: element "PARA" undefined jade:history.sgml:83:15:E: element "PRODUCTNAME" undefined jade:history.sgml:88:31:E: element "SECT2" undefined jade:history.sgml:89:8:E: element "TITLE" undefined jade:history.sgml:89:21:E: element "PRODUCTNAME" undefined jade:history.sgml:91:38:E: element "INDEXTERM" undefined jade:history.sgml:92:11:E: element "PRIMARY" undefined jade:history.sgml:95:7:E: element "PARA" undefined jade:history.sgml:97:18:E: element "PRODUCTNAME" undefined jade:history.sgml:98:15:E: element "PRODUCTNAME" undefined jade:history.sgml:100:42:E: element "PRODUCTNAME" undefined jade:history.sgml:104:7:E: element "PARA" undefined jade:history.sgml:105:15:E: element "PRODUCTNAME" undefined jade:history.sgml:108:32:E: element "PRODUCTNAME" undefined jade:history.sgml:110:18:E: element "PRODUCTNAME" undefined jade:history.sgml:113:16:E: element "ITEMIZEDLIST" undefined jade:history.sgml:114:13:E: element "LISTITEM" undefined jade:history.sgml:115:10:E: element "PARA" undefined jade:history.sgml:117:14:E: element "ACRONYM" undefined jade:history.sgml:118:28:E: there is no attribute "LINKEND" jade:history.sgml:118:35:E: element "LINK" undefined jade:history.sgml:120:43:E: element "PRODUCTNAME" undefined jade:history.sgml:122:18:E: element "PRODUCTNAME" undefined jade:history.sgml:123:14:E: element "ACRONYM" undefined jade:history.sgml:124:47:E: element "LITERAL" undefined jade:history.sgml:129:13:E: element "LISTITEM" undefined jade:history.sgml:130:10:E: element "PARA" undefined jade:history.sgml:132:19:E: element "APPLICATION" undefined jade:history.sgml:133:38:E: element "ACRONYM" undefined jade:history.sgml:134:18:E: element "APPLICATION" undefined jade:history.sgml:135:26:E: element "APPLICATION" undefined jade:history.sgml:139:13:E: element "LISTITEM" undefined jade:history.sgml:140:10:E: element "PARA" undefined jade:history.sgml:141:40:E: element "FILENAME" undefined jade:history.sgml:142:24:E: element "ACRONYM" undefined jade:history.sgml:143:14:E: element "COMMAND" undefined jade:history.sgml:144:28:E: element "APPLICATION" undefined jade:I: maximum number of errors (200) reached; change with -E option jade:stylesheet.dsl:10:91:W: cannot generate system identifier for public text "-//Norman Walsh//DOCUMENT DocBook HTML Stylesheet//EN" jade:stylesheet.dsl:24:27:E: no style-specification or external-specification with ID "DOCBOOK" jade:stylesheet.dsl:205:10:E: mode "manifest" not defined jade:stylesheet.dsl:207:8:E: mode "htmlindex" not defined jade:stylesheet.dsl:372:5:E: reference to undefined variable "html-document" jade:stylesheet.dsl:375:6:E: "element" is not the name of any flow object class jade:stylesheet.dsl:388:16:E: "element" is not the name of any flow object class jade:stylesheet.dsl:381:16:E: "element" is not the name of any flow object class jade:stylesheet.dsl:378:12:E: reference to undefined variable "$component-title$" jade:stylesheet.dsl:377:12:E: reference to undefined variable "$component-separator$" jade:stylesheet.dsl:373:6:E: mode "head-title-mode" not defined jade:stylesheet.dsl:374:17:E: reference to undefined variable "element-title-string" jade:stylesheet.dsl:369:19:E: reference to undefined variable "node-list-filter-by-gi" jade:stylesheet.dsl:371:26:E: reference to undefined variable "normalize" jade:stylesheet.dsl:366:21:E: reference to undefined variable "node-list-filter-by-gi" jade:stylesheet.dsl:368:28:E: reference to undefined variable "normalize" jade:stylesheet.dsl:363:19:E: reference to undefined variable "node-list-filter-by-not-gi" jade:stylesheet.dsl:365:26:E: reference to undefined variable "normalize" jade:stylesheet.dsl:270:9:E: "empty-element" is not the name of any flow object class jade:stylesheet.dsl:258:5:E: reference to undefined variable "para-check" jade:stylesheet.dsl:257:5:E: reference to undefined variable "$admonition$" jade:stylesheet.dsl:256:5:E: reference to undefined variable "para-check" jade:stylesheet.dsl:74:9:E: reference to undefined variable "$charseq$" jade:stylesheet.dsl:79:17:E: reference to undefined variable "%arg-choice-opt-close-str%" jade:stylesheet.dsl:78:9:E: reference to undefined variable "$charseq$" jade:stylesheet.dsl:77:17:E: reference to undefined variable "%arg-choice-opt-open-str%" jade:stylesheet.dsl:71:33:E: reference to undefined variable "normalize" jade:stylesheet.dsl:67:36:E: reference to undefined variable "$bold-seq$" jade:stylesheet.dsl:66:18:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:65:15:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:64:16:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:63:17:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:62:21:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:61:22:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:60:20:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:59:17:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:58:18:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:57:25:E: reference to undefined variable "$italic-seq$" jade:stylesheet.dsl:56:16:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:55:18:E: reference to undefined variable "$mono-seq$" jade:stylesheet.dsl:156:31:E: reference to undefined variable "$charseq$" jade:stylesheet.dsl:158:31:E: reference to undefined variable "$charseq$" jade:stylesheet.dsl:395:7:E: "element" is not the name of any flow object class jade:stylesheet.dsl:397:13:E: reference to undefined variable "element-title-sosofo" PostgreSQL 9.6devel Documentation The PostgreSQL Global Development Group PostgreSQL 9.6devel 2016 1996-2016 The PostgreSQL Global Development Group Legal Notice PostgreSQL is Copyright 1996-2016 by the PostgreSQL Global Development Group. Postgres95 is Copyright 1994-5 by the Regents of the University of California. Permission to use, copy, modify, and distribute this software and its documentation for any purpose, without fee, and without a written agreement is hereby granted, provided that the above copyright notice and this paragraph and the following two paragraphs appear in all copies. IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN AS-IS BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. Preface This book is the official documentation of PostgreSQL. It has been written by the PostgreSQL developers and other volunteers in parallel to the development of the PostgreSQL software. It describes all the functionality that the current version of PostgreSQL officially supports. To make the large amount of information about PostgreSQL manageable, this book has been organized in several parts. Each part is targeted at a different class of users, or at users in different stages of their PostgreSQL experience: is an informal introduction for new users. documents the SQL query language environment, including data types and functions, as well as user-level performance tuning. Every PostgreSQL user should read this. describes the installation and administration of the server. Everyone who runs a PostgreSQL server, be it for private use or for others, should read this part. describes the programming interfaces for PostgreSQL client programs. contains information for advanced users about the extensibility capabilities of the server. Topics include user-defined data types and functions. contains reference information about SQL commands, client and server programs. This part supports the other parts with structured information sorted by command or program. contains assorted information that might be of use to PostgreSQL developers. What is PostgreSQL? PostgreSQL is an object-relational database management system (ORDBMS) based on POSTGRES, Version 4.2, developed at the University of California at Berkeley Computer Science Department. POSTGRES pioneered many concepts that only became available in some commercial database systems much later. PostgreSQL is an open-source descendant of this original Berkeley code. It supports a large part of the SQL standard and offers many modern features: complex queries foreign keys triggers updatable views transactional integrity multiversion concurrency control Also, PostgreSQL can be extended by the user in many ways, for example by adding new data types functions operators aggregate functions index methods procedural languages And because of the liberal license, PostgreSQL can be used, modified, and distributed by anyone free of charge for any purpose, be it private, commercial, or academic. A Brief History of PostgreSQL history of PostgreSQL The object-relational database management system now known as PostgreSQL is derived from the POSTGRES package written at the University of California at Berkeley. With over two decades of development behind it, PostgreSQL is now the most advanced open-source database available anywhere. The Berkeley POSTGRES Project POSTGRES The POSTGRES project, led by Professor Michael Stonebraker, was sponsored by the Defense Advanced Research Projects Agency (DARPA), the Army Research Office (ARO), the National Science Foundation (NSF), and ESL, Inc. The implementation of POSTGRES began in 1986. The initial concepts for the system were presented in , and the definition of the initial data model appeared in . The design of the rule system at that time was described in . The rationale and architecture of the storage manager were detailed in . POSTGRES has undergone several major releases since then. The first demoware system became operational in 1987 and was shown at the 1988 ACM-SIGMOD Conference. Version 1, described in , was released to a few external users in June 1989. In response to a critique of the first rule system (), the rule system was redesigned (), and Version 2 was released in June 1990 with the new rule system. Version 3 appeared in 1991 and added support for multiple storage managers, an improved query executor, and a rewritten rule system. For the most part, subsequent releases until Postgres95 (see below) focused on portability and reliability. POSTGRES has been used to implement many different research and production applications. These include: a financial data analysis system, a jet engine performance monitoring package, an asteroid tracking database, a medical information database, and several geographic information systems. POSTGRES has also been used as an educational tool at several universities. Finally, Illustra Information Technologies (later merged into Informix, which is now owned by IBM) picked up the code and commercialized it. In late 1992, POSTGRES became the primary data manager for the Sequoia 2000 scientific computing project. The size of the external user community nearly doubled during 1993. It became increasingly obvious that maintenance of the prototype code and support was taking up large amounts of time that should have been devoted to database research. In an effort to reduce this support burden, the Berkeley POSTGRES project officially ended with Version 4.2. Postgres95 Postgres95 In 1994, Andrew Yu and Jolly Chen added an SQL language interpreter to POSTGRES. Under a new name, Postgres95 was subsequently released to the web to find its own way in the world as an open-source descendant of the original POSTGRES Berkeley code. Postgres95 code was completely ANSI C and trimmed in size by 25%. Many internal changes improved performance and maintainability. Postgres95 release 1.0.x ran about 30-50% faster on the Wisconsin Benchmark compared to POSTGRES, Version 4.2. Apart from bug fixes, the following were the major enhancements: The query language PostQUEL was replaced with SQL (implemented in the server). (Interface library libpq was named after PostQUEL.) Subqueries were not supported until PostgreSQL (see below), but they could be imitated in Postgres95 with user-defined SQL functions. Aggregate functions were re-implemented. Support for the query clause was also added. A new program (psql) was provided for interactive SQL queries, which used GNU Readline. This largely superseded the old monitor program. A new front-end library, libpgtcl, supported Tcl-based clients. A sample shell, , provided new Tcl commands to interface make: *** [HTML.index] Error 1