diff options
author | Tom Lane <tgl@sss.pgh.pa.us> | 2007-06-08 20:26:18 +0000 |
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committer | Tom Lane <tgl@sss.pgh.pa.us> | 2007-06-08 20:26:18 +0000 |
commit | 4213e5f0dbed36d7452f385782eeaa2c8a866173 (patch) | |
tree | a9d9250258d5da3774c3d028afacf0f2735d08b5 /doc/src | |
parent | a3e3389913b47cc600d0588fe395da976b61806c (diff) |
Add note that LIMIT without ORDER BY can produce outright nondeterministic
results. Necessary due to introduction of syncscan patch.
Diffstat (limited to 'doc/src')
-rw-r--r-- | doc/src/sgml/ref/select.sgml | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 0f1ada97cb6..2165a63d4a1 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.100 2007/05/15 19:13:55 neilc Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.101 2007/06/08 20:26:18 tgl Exp $ PostgreSQL documentation --> @@ -810,6 +810,14 @@ OFFSET <replaceable class="parameter">start</replaceable> to deliver the results of a query in any particular order unless <literal>ORDER BY</> is used to constrain the order. </para> + + <para> + It is even possible for repeated executions of the same <literal>LIMIT</> + query to return different subsets of the rows of a table, if there + is not an <literal>ORDER BY</> to enforce selection of a deterministic + subset. Again, this is not a bug; determinism of the results is + simply not guaranteed in such a case. + </para> </refsect2> <refsect2 id="SQL-FOR-UPDATE-SHARE"> |