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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Character Set Support</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 9.2.24 Documentation" HREF="index.html"><LINK REL="UP" TITLE="Localization" HREF="charset.html"><LINK REL="PREVIOUS" TITLE="Collation Support" HREF="collation.html"><LINK REL="NEXT" TITLE="Routine Database Maintenance Tasks" HREF="maintenance.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2017-11-06T22:43:11"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" ><A HREF="index.html" >PostgreSQL 9.2.24 Documentation</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A TITLE="Collation Support" HREF="collation.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="charset.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 22. Localization</TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="Routine Database Maintenance Tasks" HREF="maintenance.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="MULTIBYTE" >22.3. Character Set Support</A ></H1 ><P > The character set support in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > allows you to store text in a variety of character sets (also called encodings), including single-byte character sets such as the ISO 8859 series and multiple-byte character sets such as <ACRONYM CLASS="ACRONYM" >EUC</ACRONYM > (Extended Unix Code), UTF-8, and Mule internal code. All supported character sets can be used transparently by clients, but a few are not supported for use within the server (that is, as a server-side encoding). The default character set is selected while initializing your <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > database cluster using <TT CLASS="COMMAND" >initdb</TT >. It can be overridden when you create a database, so you can have multiple databases each with a different character set. </P ><P > An important restriction, however, is that each database's character set must be compatible with the database's <TT CLASS="ENVAR" >LC_CTYPE</TT > (character classification) and <TT CLASS="ENVAR" >LC_COLLATE</TT > (string sort order) locale settings. For <TT CLASS="LITERAL" >C</TT > or <TT CLASS="LITERAL" >POSIX</TT > locale, any character set is allowed, but for other locales there is only one character set that will work correctly. (On Windows, however, UTF-8 encoding can be used with any locale.) </P ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="MULTIBYTE-CHARSET-SUPPORTED" >22.3.1. Supported Character Sets</A ></H2 ><P > <A HREF="multibyte.html#CHARSET-TABLE" >Table 22-1</A > shows the character sets available for use in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN >. </P ><DIV CLASS="TABLE" ><A NAME="CHARSET-TABLE" ></A ><P ><B >Table 22-1. <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > Character Sets</B ></P ><TABLE BORDER="1" CLASS="CALSTABLE" ><COL><COL><COL><COL><COL><COL><THEAD ><TR ><TH >Name</TH ><TH >Description</TH ><TH >Language</TH ><TH >Server?</TH ><TH >Bytes/Char</TH ><TH >Aliases</TH ></TR ></THEAD ><TBODY ><TR ><TD ><TT CLASS="LITERAL" >BIG5</TT ></TD ><TD >Big Five</TD ><TD >Traditional Chinese</TD ><TD >No</TD ><TD >1-2</TD ><TD ><TT CLASS="LITERAL" >WIN950</TT >, <TT CLASS="LITERAL" >Windows950</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_CN</TT ></TD ><TD >Extended UNIX Code-CN</TD ><TD >Simplified Chinese</TD ><TD >Yes</TD ><TD >1-3</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_JP</TT ></TD ><TD >Extended UNIX Code-JP</TD ><TD >Japanese</TD ><TD >Yes</TD ><TD >1-3</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_JIS_2004</TT ></TD ><TD >Extended UNIX Code-JP, JIS X 0213</TD ><TD >Japanese</TD ><TD >Yes</TD ><TD >1-3</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_KR</TT ></TD ><TD >Extended UNIX Code-KR</TD ><TD >Korean</TD ><TD >Yes</TD ><TD >1-3</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_TW</TT ></TD ><TD >Extended UNIX Code-TW</TD ><TD >Traditional Chinese, Taiwanese</TD ><TD >Yes</TD ><TD >1-3</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >GB18030</TT ></TD ><TD >National Standard</TD ><TD >Chinese</TD ><TD >No</TD ><TD >1-4</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >GBK</TT ></TD ><TD >Extended National Standard</TD ><TD >Simplified Chinese</TD ><TD >No</TD ><TD >1-2</TD ><TD ><TT CLASS="LITERAL" >WIN936</TT >, <TT CLASS="LITERAL" >Windows936</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >ISO_8859_5</TT ></TD ><TD >ISO 8859-5, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 113</TD ><TD >Latin/Cyrillic</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >ISO_8859_6</TT ></TD ><TD >ISO 8859-6, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 114</TD ><TD >Latin/Arabic</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >ISO_8859_7</TT ></TD ><TD >ISO 8859-7, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 118</TD ><TD >Latin/Greek</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >ISO_8859_8</TT ></TD ><TD >ISO 8859-8, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 121</TD ><TD >Latin/Hebrew</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >JOHAB</TT ></TD ><TD ><ACRONYM CLASS="ACRONYM" >JOHAB</ACRONYM ></TD ><TD >Korean (Hangul)</TD ><TD >No</TD ><TD >1-3</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >KOI8R</TT ></TD ><TD ><ACRONYM CLASS="ACRONYM" >KOI</ACRONYM >8-R</TD ><TD >Cyrillic (Russian)</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >KOI8</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >KOI8U</TT ></TD ><TD ><ACRONYM CLASS="ACRONYM" >KOI</ACRONYM >8-U</TD ><TD >Cyrillic (Ukrainian)</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN1</TT ></TD ><TD >ISO 8859-1, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 94</TD ><TD >Western European</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO88591</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN2</TT ></TD ><TD >ISO 8859-2, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 94</TD ><TD >Central European</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO88592</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN3</TT ></TD ><TD >ISO 8859-3, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 94</TD ><TD >South European</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO88593</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN4</TT ></TD ><TD >ISO 8859-4, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 94</TD ><TD >North European</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO88594</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN5</TT ></TD ><TD >ISO 8859-9, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 128</TD ><TD >Turkish</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO88599</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN6</TT ></TD ><TD >ISO 8859-10, <ACRONYM CLASS="ACRONYM" >ECMA</ACRONYM > 144</TD ><TD >Nordic</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO885910</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN7</TT ></TD ><TD >ISO 8859-13</TD ><TD >Baltic</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO885913</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN8</TT ></TD ><TD >ISO 8859-14</TD ><TD >Celtic</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO885914</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN9</TT ></TD ><TD >ISO 8859-15</TD ><TD >LATIN1 with Euro and accents</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO885915</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN10</TT ></TD ><TD >ISO 8859-16, <ACRONYM CLASS="ACRONYM" >ASRO</ACRONYM > SR 14111</TD ><TD >Romanian</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ISO885916</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >MULE_INTERNAL</TT ></TD ><TD >Mule internal code</TD ><TD >Multilingual Emacs</TD ><TD >Yes</TD ><TD >1-4</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >SJIS</TT ></TD ><TD >Shift JIS</TD ><TD >Japanese</TD ><TD >No</TD ><TD >1-2</TD ><TD ><TT CLASS="LITERAL" >Mskanji</TT >, <TT CLASS="LITERAL" >ShiftJIS</TT >, <TT CLASS="LITERAL" >WIN932</TT >, <TT CLASS="LITERAL" >Windows932</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >SHIFT_JIS_2004</TT ></TD ><TD >Shift JIS, JIS X 0213</TD ><TD >Japanese</TD ><TD >No</TD ><TD >1-2</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >SQL_ASCII</TT ></TD ><TD >unspecified (see text)</TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >any</I ></SPAN ></TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >UHC</TT ></TD ><TD >Unified Hangul Code</TD ><TD >Korean</TD ><TD >No</TD ><TD >1-2</TD ><TD ><TT CLASS="LITERAL" >WIN949</TT >, <TT CLASS="LITERAL" >Windows949</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >UTF8</TT ></TD ><TD >Unicode, 8-bit</TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >all</I ></SPAN ></TD ><TD >Yes</TD ><TD >1-4</TD ><TD ><TT CLASS="LITERAL" >Unicode</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN866</TT ></TD ><TD >Windows CP866</TD ><TD >Cyrillic</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ALT</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN874</TT ></TD ><TD >Windows CP874</TD ><TD >Thai</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1250</TT ></TD ><TD >Windows CP1250</TD ><TD >Central European</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1251</TT ></TD ><TD >Windows CP1251</TD ><TD >Cyrillic</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >WIN</TT ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1252</TT ></TD ><TD >Windows CP1252</TD ><TD >Western European</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1253</TT ></TD ><TD >Windows CP1253</TD ><TD >Greek</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1254</TT ></TD ><TD >Windows CP1254</TD ><TD >Turkish</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1255</TT ></TD ><TD >Windows CP1255</TD ><TD >Hebrew</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1256</TT ></TD ><TD >Windows CP1256</TD ><TD >Arabic</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1257</TT ></TD ><TD >Windows CP1257</TD ><TD >Baltic</TD ><TD >Yes</TD ><TD >1</TD ><TD > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1258</TT ></TD ><TD >Windows CP1258</TD ><TD >Vietnamese</TD ><TD >Yes</TD ><TD >1</TD ><TD ><TT CLASS="LITERAL" >ABC</TT >, <TT CLASS="LITERAL" >TCVN</TT >, <TT CLASS="LITERAL" >TCVN5712</TT >, <TT CLASS="LITERAL" >VSCII</TT ></TD ></TR ></TBODY ></TABLE ></DIV ><P > Not all client <ACRONYM CLASS="ACRONYM" >API</ACRONYM >s support all the listed character sets. For example, the <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > JDBC driver does not support <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >LATIN6</TT >, <TT CLASS="LITERAL" >LATIN8</TT >, and <TT CLASS="LITERAL" >LATIN10</TT >. </P ><P > The <TT CLASS="LITERAL" >SQL_ASCII</TT > setting behaves considerably differently from the other settings. When the server character set is <TT CLASS="LITERAL" >SQL_ASCII</TT >, the server interprets byte values 0-127 according to the ASCII standard, while byte values 128-255 are taken as uninterpreted characters. No encoding conversion will be done when the setting is <TT CLASS="LITERAL" >SQL_ASCII</TT >. Thus, this setting is not so much a declaration that a specific encoding is in use, as a declaration of ignorance about the encoding. In most cases, if you are working with any non-ASCII data, it is unwise to use the <TT CLASS="LITERAL" >SQL_ASCII</TT > setting because <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > will be unable to help you by converting or validating non-ASCII characters. </P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN33549" >22.3.2. Setting the Character Set</A ></H2 ><P > <TT CLASS="COMMAND" >initdb</TT > defines the default character set (encoding) for a <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > cluster. For example, </P><PRE CLASS="SCREEN" >initdb -E EUC_JP</PRE ><P> sets the default character set to <TT CLASS="LITERAL" >EUC_JP</TT > (Extended Unix Code for Japanese). You can use <TT CLASS="OPTION" >--encoding</TT > instead of <TT CLASS="OPTION" >-E</TT > if you prefer longer option strings. If no <TT CLASS="OPTION" >-E</TT > or <TT CLASS="OPTION" >--encoding</TT > option is given, <TT CLASS="COMMAND" >initdb</TT > attempts to determine the appropriate encoding to use based on the specified or default locale. </P ><P > You can specify a non-default encoding at database creation time, provided that the encoding is compatible with the selected locale: </P><PRE CLASS="SCREEN" >createdb -E EUC_KR -T template0 --lc-collate=ko_KR.euckr --lc-ctype=ko_KR.euckr korean</PRE ><P> This will create a database named <TT CLASS="LITERAL" >korean</TT > that uses the character set <TT CLASS="LITERAL" >EUC_KR</TT >, and locale <TT CLASS="LITERAL" >ko_KR</TT >. Another way to accomplish this is to use this SQL command: </P><PRE CLASS="PROGRAMLISTING" >CREATE DATABASE korean WITH ENCODING 'EUC_KR' LC_COLLATE='ko_KR.euckr' LC_CTYPE='ko_KR.euckr' TEMPLATE=template0;</PRE ><P> Notice that the above commands specify copying the <TT CLASS="LITERAL" >template0</TT > database. When copying any other database, the encoding and locale settings cannot be changed from those of the source database, because that might result in corrupt data. For more information see <A HREF="manage-ag-templatedbs.html" >Section 21.3</A >. </P ><P > The encoding for a database is stored in the system catalog <TT CLASS="LITERAL" >pg_database</TT >. You can see it by using the <TT CLASS="COMMAND" >psql</TT > <TT CLASS="OPTION" >-l</TT > option or the <TT CLASS="COMMAND" >\l</TT > command. </P><PRE CLASS="SCREEN" >$ <KBD CLASS="USERINPUT" >psql -l</KBD > List of databases Name | Owner | Encoding | Collation | Ctype | Access Privileges -----------+----------+-----------+-------------+-------------+------------------------------------- clocaledb | hlinnaka | SQL_ASCII | C | C | englishdb | hlinnaka | UTF8 | en_GB.UTF8 | en_GB.UTF8 | japanese | hlinnaka | UTF8 | ja_JP.UTF8 | ja_JP.UTF8 | korean | hlinnaka | EUC_KR | ko_KR.euckr | ko_KR.euckr | postgres | hlinnaka | UTF8 | fi_FI.UTF8 | fi_FI.UTF8 | template0 | hlinnaka | UTF8 | fi_FI.UTF8 | fi_FI.UTF8 | {=c/hlinnaka,hlinnaka=CTc/hlinnaka} template1 | hlinnaka | UTF8 | fi_FI.UTF8 | fi_FI.UTF8 | {=c/hlinnaka,hlinnaka=CTc/hlinnaka} (7 rows)</PRE ><P> </P ><DIV CLASS="IMPORTANT" ><BLOCKQUOTE CLASS="IMPORTANT" ><P ><B >Important: </B > On most modern operating systems, <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > can determine which character set is implied by the <TT CLASS="ENVAR" >LC_CTYPE</TT > setting, and it will enforce that only the matching database encoding is used. On older systems it is your responsibility to ensure that you use the encoding expected by the locale you have selected. A mistake in this area is likely to lead to strange behavior of locale-dependent operations such as sorting. </P ><P > <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > will allow superusers to create databases with <TT CLASS="LITERAL" >SQL_ASCII</TT > encoding even when <TT CLASS="ENVAR" >LC_CTYPE</TT > is not <TT CLASS="LITERAL" >C</TT > or <TT CLASS="LITERAL" >POSIX</TT >. As noted above, <TT CLASS="LITERAL" >SQL_ASCII</TT > does not enforce that the data stored in the database has any particular encoding, and so this choice poses risks of locale-dependent misbehavior. Using this combination of settings is deprecated and may someday be forbidden altogether. </P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN33587" >22.3.3. Automatic Character Set Conversion Between Server and Client</A ></H2 ><P > <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > supports automatic character set conversion between server and client for certain character set combinations. The conversion information is stored in the <TT CLASS="LITERAL" >pg_conversion</TT > system catalog. <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > comes with some predefined conversions, as shown in <A HREF="multibyte.html#MULTIBYTE-TRANSLATION-TABLE" >Table 22-2</A >. You can create a new conversion using the SQL command <TT CLASS="COMMAND" >CREATE CONVERSION</TT >. </P ><DIV CLASS="TABLE" ><A NAME="MULTIBYTE-TRANSLATION-TABLE" ></A ><P ><B >Table 22-2. Client/Server Character Set Conversions</B ></P ><TABLE BORDER="1" CLASS="CALSTABLE" ><COL><COL><THEAD ><TR ><TH >Server Character Set</TH ><TH >Available Client Character Sets</TH ></TR ></THEAD ><TBODY ><TR ><TD ><TT CLASS="LITERAL" >BIG5</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >not supported as a server encoding</I ></SPAN > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_CN</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >EUC_CN</I ></SPAN >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_JP</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >EUC_JP</I ></SPAN >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >SJIS</TT >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_KR</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >EUC_KR</I ></SPAN >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >EUC_TW</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >EUC_TW</I ></SPAN >, <TT CLASS="LITERAL" >BIG5</TT >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >GB18030</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >not supported as a server encoding</I ></SPAN > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >GBK</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >not supported as a server encoding</I ></SPAN > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >ISO_8859_5</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >ISO_8859_5</I ></SPAN >, <TT CLASS="LITERAL" >KOI8R</TT >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT >, <TT CLASS="LITERAL" >WIN866</TT >, <TT CLASS="LITERAL" >WIN1251</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >ISO_8859_6</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >ISO_8859_6</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >ISO_8859_7</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >ISO_8859_7</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >ISO_8859_8</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >ISO_8859_8</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >JOHAB</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >JOHAB</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >KOI8R</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >KOI8R</I ></SPAN >, <TT CLASS="LITERAL" >ISO_8859_5</TT >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT >, <TT CLASS="LITERAL" >WIN866</TT >, <TT CLASS="LITERAL" >WIN1251</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >KOI8U</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >KOI8U</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN1</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN1</I ></SPAN >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN2</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN2</I ></SPAN >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT >, <TT CLASS="LITERAL" >WIN1250</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN3</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN3</I ></SPAN >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN4</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN4</I ></SPAN >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN5</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN5</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN6</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN6</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN7</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN7</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN8</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN8</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN9</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN9</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >LATIN10</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >LATIN10</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >MULE_INTERNAL</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >MULE_INTERNAL</I ></SPAN >, <TT CLASS="LITERAL" >BIG5</TT >, <TT CLASS="LITERAL" >EUC_CN</TT >, <TT CLASS="LITERAL" >EUC_JP</TT >, <TT CLASS="LITERAL" >EUC_KR</TT >, <TT CLASS="LITERAL" >EUC_TW</TT >, <TT CLASS="LITERAL" >ISO_8859_5</TT >, <TT CLASS="LITERAL" >KOI8R</TT >, <TT CLASS="LITERAL" >LATIN1</TT > to <TT CLASS="LITERAL" >LATIN4</TT >, <TT CLASS="LITERAL" >SJIS</TT >, <TT CLASS="LITERAL" >WIN866</TT >, <TT CLASS="LITERAL" >WIN1250</TT >, <TT CLASS="LITERAL" >WIN1251</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >SJIS</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >not supported as a server encoding</I ></SPAN > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >SQL_ASCII</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >any (no conversion will be performed)</I ></SPAN > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >UHC</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >not supported as a server encoding</I ></SPAN > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >UTF8</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >all supported encodings</I ></SPAN > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN866</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN866</I ></SPAN >, <TT CLASS="LITERAL" >ISO_8859_5</TT >, <TT CLASS="LITERAL" >KOI8R</TT >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT >, <TT CLASS="LITERAL" >WIN1251</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN874</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN874</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1250</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1250</I ></SPAN >, <TT CLASS="LITERAL" >LATIN2</TT >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1251</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1251</I ></SPAN >, <TT CLASS="LITERAL" >ISO_8859_5</TT >, <TT CLASS="LITERAL" >KOI8R</TT >, <TT CLASS="LITERAL" >MULE_INTERNAL</TT >, <TT CLASS="LITERAL" >UTF8</TT >, <TT CLASS="LITERAL" >WIN866</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1252</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1252</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1253</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1253</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1254</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1254</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1255</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1255</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1256</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1256</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1257</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1257</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >WIN1258</TT ></TD ><TD ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >WIN1258</I ></SPAN >, <TT CLASS="LITERAL" >UTF8</TT > </TD ></TR ></TBODY ></TABLE ></DIV ><P > To enable automatic character set conversion, you have to tell <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > the character set (encoding) you would like to use in the client. There are several ways to accomplish this: <P ></P ></P><UL ><LI ><P > Using the <TT CLASS="COMMAND" >\encoding</TT > command in <SPAN CLASS="APPLICATION" >psql</SPAN >. <TT CLASS="COMMAND" >\encoding</TT > allows you to change client encoding on the fly. For example, to change the encoding to <TT CLASS="LITERAL" >SJIS</TT >, type: </P><PRE CLASS="PROGRAMLISTING" >\encoding SJIS</PRE ><P> </P ></LI ><LI ><P > <SPAN CLASS="APPLICATION" >libpq</SPAN > (<A HREF="libpq-control.html" >Section 31.10</A >) has functions to control the client encoding. </P ></LI ><LI ><P > Using <TT CLASS="COMMAND" >SET client_encoding TO</TT >. Setting the client encoding can be done with this SQL command: </P><PRE CLASS="PROGRAMLISTING" >SET CLIENT_ENCODING TO '<TT CLASS="REPLACEABLE" ><I >value</I ></TT >';</PRE ><P> Also you can use the standard SQL syntax <TT CLASS="LITERAL" >SET NAMES</TT > for this purpose: </P><PRE CLASS="PROGRAMLISTING" >SET NAMES '<TT CLASS="REPLACEABLE" ><I >value</I ></TT >';</PRE ><P> To query the current client encoding: </P><PRE CLASS="PROGRAMLISTING" >SHOW client_encoding;</PRE ><P> To return to the default encoding: </P><PRE CLASS="PROGRAMLISTING" >RESET client_encoding;</PRE ><P> </P ></LI ><LI ><P > Using <TT CLASS="ENVAR" >PGCLIENTENCODING</TT >. If the environment variable <TT CLASS="ENVAR" >PGCLIENTENCODING</TT > is defined in the client's environment, that client encoding is automatically selected when a connection to the server is made. (This can subsequently be overridden using any of the other methods mentioned above.) </P ></LI ><LI ><P > Using the configuration variable <A HREF="runtime-config-client.html#GUC-CLIENT-ENCODING" >client_encoding</A >. If the <TT CLASS="VARNAME" >client_encoding</TT > variable is set, that client encoding is automatically selected when a connection to the server is made. (This can subsequently be overridden using any of the other methods mentioned above.) </P ></LI ></UL ><P> </P ><P > If the conversion of a particular character is not possible — suppose you chose <TT CLASS="LITERAL" >EUC_JP</TT > for the server and <TT CLASS="LITERAL" >LATIN1</TT > for the client, and some Japanese characters are returned that do not have a representation in <TT CLASS="LITERAL" >LATIN1</TT > — an error is reported. </P ><P > If the client character set is defined as <TT CLASS="LITERAL" >SQL_ASCII</TT >, encoding conversion is disabled, regardless of the server's character set. Just as for the server, use of <TT CLASS="LITERAL" >SQL_ASCII</TT > is unwise unless you are working with all-ASCII data. </P ></DIV ><DIV CLASS="SECT2" ><H2 CLASS="SECT2" ><A NAME="AEN33916" >22.3.4. Further Reading</A ></H2 ><P > These are good sources to start learning about various kinds of encoding systems. <P ></P ></P><DIV CLASS="VARIABLELIST" ><DL ><DT ><I CLASS="CITETITLE" >CJKV Information Processing: Chinese, Japanese, Korean & Vietnamese Computing</I ></DT ><DD ><P > Contains detailed explanations of <TT CLASS="LITERAL" >EUC_JP</TT >, <TT CLASS="LITERAL" >EUC_CN</TT >, <TT CLASS="LITERAL" >EUC_KR</TT >, <TT CLASS="LITERAL" >EUC_TW</TT >. </P ></DD ><DT ><A HREF="http://www.unicode.org/" TARGET="_top" >http://www.unicode.org/</A ></DT ><DD ><P > The web site of the Unicode Consortium. </P ></DD ><DT >RFC 3629</DT ><DD ><P > <ACRONYM CLASS="ACRONYM" >UTF</ACRONYM >-8 (8-bit UCS/Unicode Transformation Format) is defined here. </P ></DD ></DL ></DIV ><P> </P ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="collation.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="maintenance.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Collation Support</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="charset.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Routine Database Maintenance Tasks</TD ></TR ></TABLE ></DIV ></BODY ></HTML >