From c2f60711d25b256dbe2c1ddce833c5c69ca051cc Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 29 Aug 2006 22:25:08 +0000 Subject: Create a FETCH_COUNT parameter that causes psql to execute SELECT-like queries via a cursor, fetching a limited number of rows at a time and therefore not risking exhausting memory. A disadvantage of the scheme is that 'aligned' output mode will align each group of rows independently leading to odd-looking output, but all the other output formats work reasonably well. Chris Mair, with some additional hacking by moi. --- doc/src/sgml/ref/psql-ref.sgml | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) (limited to 'doc/src') diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index 97809bb7b19..d6528d0bc10 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -1,5 +1,5 @@ @@ -2007,6 +2007,33 @@ bar + + FETCH_COUNT + + + If this variable is set to an integer value > 0, + the results of SELECT queries are fetched + and displayed in groups of that many rows, rather than the + default behavior of collecting the entire result set before + display. Therefore only a + limited amount of memory is used, regardless of the size of + the result set. Settings of 100 to 1000 are commonly used + when enabling this feature. + Keep in mind that when using this feature, a query may + fail after having already displayed some rows. + + + + Although you can use any output format with this feature, + the default aligned format tends to look bad + because each group of FETCH_COUNT rows + will be formatted separately, leading to varying column + widths across the row groups. The other output formats work better. + + + + + HISTCONTROL -- cgit v1.2.3