diff options
Diffstat (limited to 'doc/src/sgml/ref/alter_table.sgml')
| -rw-r--r-- | doc/src/sgml/ref/alter_table.sgml | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index 1e4f26c13f6..541e093a519 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -240,9 +240,10 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM provided none of the records in the table contain a <literal>NULL</literal> value for the column. Ordinarily this is checked during the <literal>ALTER TABLE</literal> by scanning the - entire table; however, if a valid <literal>CHECK</literal> constraint is - found which proves no <literal>NULL</literal> can exist, then the - table scan is skipped. + entire table, unless <literal>NOT VALID</literal> is specified; + however, if a valid <literal>CHECK</literal> constraint exists + (and is not dropped in the same command) which proves no + <literal>NULL</literal> can exist, then the table scan is skipped. If a column has an invalid not-null constraint, <literal>SET NOT NULL</literal> validates it. </para> |