doc/src/sgml/ref/alter_database.sgml

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   2 doc/src/sgml/ref/alter_database.sgml
   3 PostgreSQL documentation
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   5
   6 <refentry id="sql-alterdatabase">
   7  <indexterm zone="sql-alterdatabase">
   8   <primary>ALTER DATABASE</primary>
   9  </indexterm>
  10
  11  <refmeta>
  12   <refentrytitle>ALTER DATABASE</refentrytitle>
  13   <manvolnum>7</manvolnum>
  14   <refmiscinfo>SQL - Language Statements</refmiscinfo>
  15  </refmeta>
  16
  17  <refnamediv>
  18   <refname>ALTER DATABASE</refname>
  19   <refpurpose>change a database</refpurpose>
  20  </refnamediv>
  21
  22  <refsynopsisdiv>
  23 <synopsis>
  24 ALTER DATABASE <replaceable class="parameter">name</replaceable> [ [ WITH ] <replaceable class="parameter">option</replaceable> [ ... ] ]
  25
  26 <phrase>where <replaceable class="parameter">option</replaceable> can be:</phrase>
  27
  28     ALLOW_CONNECTIONS <replaceable class="parameter">allowconn</replaceable>
  29     CONNECTION LIMIT <replaceable class="parameter">connlimit</replaceable>
  30     IS_TEMPLATE <replaceable class="parameter">istemplate</replaceable>
  31
  32 ALTER DATABASE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
  33
  34 ALTER DATABASE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
  35
  36 ALTER DATABASE <replaceable class="parameter">name</replaceable> SET TABLESPACE <replaceable class="parameter">new_tablespace</replaceable>
  37
  38 ALTER DATABASE <replaceable class="parameter">name</replaceable> REFRESH COLLATION VERSION
  39
  40 ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> { TO | = } { <replaceable>value</replaceable> | DEFAULT }
  41 ALTER DATABASE <replaceable class="parameter">name</replaceable> SET <replaceable>configuration_parameter</replaceable> FROM CURRENT
  42 ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET <replaceable>configuration_parameter</replaceable>
  43 ALTER DATABASE <replaceable class="parameter">name</replaceable> RESET ALL
  44 </synopsis>
  45  </refsynopsisdiv>
  46
  47  <refsect1>
  48   <title>Description</title>
  49
  50   <para>
  51    <command>ALTER DATABASE</command> changes the attributes
  52    of a database.
  53   </para>
  54
  55   <para>
  56    The first form changes certain per-database settings.  (See below for
  57    details.)  Only the database owner or a superuser can change these settings.
  58   </para>
  59
  60   <para>
  61    The second form changes the name of the database.  Only the database
  62    owner or a superuser can rename a database; non-superuser owners must
  63    also have the
  64    <literal>CREATEDB</literal> privilege.  The current database cannot
  65    be renamed.  (Connect to a different database if you need to do
  66    that.)
  67   </para>
  68
  69   <para>
  70    The third form changes the owner of the database.
  71    To alter the owner, you must be able to <literal>SET ROLE</literal> to the
  72    new owning role, and you must have the
  73    <literal>CREATEDB</literal> privilege.
  74    (Note that superusers have all these privileges automatically.)
  75   </para>
  76
  77   <para>
  78    The fourth form changes the default tablespace of the database.
  79    Only the database owner or a superuser can do this; you must also have
  80    create privilege for the new tablespace.
  81    This command physically moves any tables or indexes in the database's old
  82    default tablespace to the new tablespace.  The new default tablespace
  83    must be empty for this database, and no one can be connected to
  84    the database.  Tables and indexes in non-default tablespaces are
  85    unaffected.
  86   </para>
  87
  88   <para>
  89    The remaining forms change the session default for a run-time
  90    configuration variable for a <productname>PostgreSQL</productname>
  91    database. Whenever a new session is subsequently started in that
  92    database, the specified value becomes the session default value.
  93    The database-specific default overrides whatever setting is present
  94    in <filename>postgresql.conf</filename> or has been received from the
  95    <command>postgres</command> command line.  Only the database
  96    owner or a superuser can change the session defaults for a
  97    database.  Certain variables cannot be set this way, or can only be
  98    set by a superuser.
  99   </para>
 100  </refsect1>
 101
 102  <refsect1>
 103   <title>Parameters</title>
 104
 105     <variablelist>
 106      <varlistentry>
 107       <term><replaceable class="parameter">name</replaceable></term>
 108       <listitem>
 109        <para>
 110         The name of the database whose attributes are to be altered.
 111        </para>
 112       </listitem>
 113      </varlistentry>
 114
 115       <varlistentry>
 116        <term><replaceable class="parameter">allowconn</replaceable></term>
 117        <listitem>
 118         <para>
 119          If false then no one can connect to this database.
 120         </para>
 121        </listitem>
 122       </varlistentry>
 123
 124       <varlistentry>
 125       <term><replaceable class="parameter">connlimit</replaceable></term>
 126       <listitem>
 127        <para>
 128         How many concurrent connections can be made
 129         to this database.  -1 means no limit.
 130        </para>
 131       </listitem>
 132      </varlistentry>
 133
 134      <varlistentry>
 135        <term><replaceable class="parameter">istemplate</replaceable></term>
 136        <listitem>
 137         <para>
 138          If true, then this database can be cloned by any user with <literal>CREATEDB</literal>
 139          privileges; if false, then only superusers or the owner of the
 140          database can clone it.
 141         </para>
 142        </listitem>
 143       </varlistentry>
 144
 145    <varlistentry>
 146     <term><replaceable>new_name</replaceable></term>
 147     <listitem>
 148      <para>
 149       The new name of the database.
 150      </para>
 151     </listitem>
 152    </varlistentry>
 153
 154    <varlistentry>
 155     <term><replaceable class="parameter">new_owner</replaceable></term>
 156     <listitem>
 157      <para>
 158       The new owner of the database.
 159      </para>
 160     </listitem>
 161    </varlistentry>
 162
 163    <varlistentry>
 164     <term><replaceable class="parameter">new_tablespace</replaceable></term>
 165     <listitem>
 166      <para>
 167       The new default tablespace of the database.
 168      </para>
 169
 170      <para>
 171       This form of the command cannot be executed inside a transaction block.
 172      </para>
 173     </listitem>
 174    </varlistentry>
 175
 176    <varlistentry>
 177     <term><literal>REFRESH COLLATION VERSION</literal></term>
 178     <listitem>
 179      <para>
 180       Update the database collation version.  See <xref
 181       linkend="sql-altercollation-notes"/> for background.
 182      </para>
 183     </listitem>
 184    </varlistentry>
 185
 186      <varlistentry>
 187       <term><replaceable>configuration_parameter</replaceable></term>
 188       <term><replaceable>value</replaceable></term>
 189       <listitem>
 190        <para>
 191         Set this database's session default for the specified configuration
 192         parameter to the given value.  If
 193         <replaceable>value</replaceable> is <literal>DEFAULT</literal>
 194         or, equivalently, <literal>RESET</literal> is used, the
 195         database-specific setting is removed, so the system-wide default
 196         setting will be inherited in new sessions.  Use <literal>RESET
 197         ALL</literal> to clear all database-specific settings.
 198         <literal>SET FROM CURRENT</literal> saves the session's current value of
 199         the parameter as the database-specific value.
 200        </para>
 201
 202        <para>
 203         See <xref linkend="sql-set"/> and <xref linkend="runtime-config"/>
 204         for more information about allowed parameter names
 205         and values.
 206        </para>
 207       </listitem>
 208      </varlistentry>
 209   </variablelist>
 210  </refsect1>
 211
 212  <refsect1>
 213   <title>Notes</title>
 214
 215   <para>
 216    It is also possible to tie a session default to a specific role
 217    rather than to a database; see
 218    <xref linkend="sql-alterrole"/>.
 219    Role-specific settings override database-specific
 220    ones if there is a conflict.
 221   </para>
 222  </refsect1>
 223
 224  <refsect1>
 225   <title>Examples</title>
 226
 227   <para>
 228    To disable index scans by default in the database
 229    <literal>test</literal>:
 230
 231 <programlisting>
 232 ALTER DATABASE test SET enable_indexscan TO off;
 233 </programlisting></para>
 234  </refsect1>
 235
 236  <refsect1>
 237   <title>Compatibility</title>
 238
 239   <para>
 240    The <command>ALTER DATABASE</command> statement is a
 241    <productname>PostgreSQL</productname> extension.
 242   </para>
 243  </refsect1>
 244
 245  <refsect1>
 246   <title>See Also</title>
 247
 248   <simplelist type="inline">
 249    <member><xref linkend="sql-createdatabase"/></member>
 250    <member><xref linkend="sql-dropdatabase"/></member>
 251    <member><xref linkend="sql-set"/></member>
 252    <member><xref linkend="sql-createtablespace"/></member>
 253   </simplelist>
 254  </refsect1>
 255 </refentry>