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| author | Stephen Frost | 2016-12-21 20:05:14 +0000 |
|---|---|---|
| committer | Stephen Frost | 2016-12-21 20:05:14 +0000 |
| commit | b5fe1d4cd93d281eef7ab6718716d169609b000a (patch) | |
| tree | 646640a973570e8eb72a145d3dce735ed2b08003 /doc/src | |
| parent | 13f51dacfab83f868df09370d10d4d9932fc0a61 (diff) | |
Improve ALTER TABLE documentation
The ALTER TABLE documentation wasn't terribly clear when it came to
which commands could be combined together and what it meant when they
were.
In particular, SET TABLESPACE *can* be combined with other commands,
when it's operating against a single table, but not when multiple tables
are being moved with ALL IN TABLESPACE. Further, the actions are
applied together but not really in 'parallel', at least today.
Pointed out by: Amit Langote
Improved wording from Tom.
Back-patch to 9.4, where the ALL IN TABLESPACE option was added.
Discussion: https://www.postgresql.org/message-id/14c535b4-13ef-0590-1b98-76af355a0763%40lab.ntt.co.jp
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/alter_table.sgml | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index 8ef0cabe77e..cc0fdffe093 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -662,10 +662,10 @@ ALTER TABLE ALL IN TABLESPACE <replaceable class="PARAMETER">name</replaceable> </para> <para> - All the actions except <literal>RENAME</literal>, - <literal>SET TABLESPACE</literal> and <literal>SET SCHEMA</literal> - can be combined into - a list of multiple alterations to apply in parallel. For example, it + All the forms of ALTER TABLE that act on a single table, except + <literal>RENAME</literal>, and <literal>SET SCHEMA</literal> + can be combined into a list of multiple alterations to applied together. + For example, it is possible to add several columns and/or alter the type of several columns in a single command. This is particularly useful with large tables, since only one pass over the table need be made. |