diff options
| -rw-r--r-- | doc/src/sgml/ref/alter_table.sgml | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index be1647937dc..2cec1864dd0 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -616,9 +616,9 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM <term><literal>SET WITHOUT OIDS</literal></term> <listitem> <para> - Backward compatibility syntax for removing the <literal>oid</literal> - system column. As oid system columns cannot be added anymore, this never - has an effect. + Backward-compatible syntax for removing the <literal>oid</literal> + system column. As <literal>oid</literal> system columns cannot be + added anymore, this never has an effect. </para> </listitem> </varlistentry> @@ -744,8 +744,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM <para> This form links the table to a composite type as though <command>CREATE TABLE OF</command> had formed it. The table's list of column names and types - must precisely match that of the composite type; the presence of - an <literal>oid</literal> system column is permitted to differ. The table must + must precisely match that of the composite type. The table must not inherit from any other table. These restrictions ensure that <command>CREATE TABLE OF</command> would permit an equivalent table definition. @@ -1178,8 +1177,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM the column contents and the old type is either binary coercible to the new type or an unconstrained domain over the new type, a table rewrite is not needed; but any indexes on the affected columns must still be rebuilt. - Adding or removing a system <literal>oid</literal> column also requires - rewriting the entire table. Table and/or index rebuilds may take a + Table and/or index rebuilds may take a significant amount of time for a large table; and will temporarily require as much as double the disk space. </para> @@ -1208,9 +1206,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM column. Thus, dropping a column is quick but it will not immediately reduce the on-disk size of your table, as the space occupied by the dropped column is not reclaimed. The space will be - reclaimed over time as existing rows are updated. (These statements do - not apply when dropping the system <literal>oid</literal> column; that is done - with an immediate rewrite.) + reclaimed over time as existing rows are updated. </para> <para> |