From e7a86f9adf7f24393fa0102d49d689bcec47d3c5 Mon Sep 17 00:00:00 2001 From: Christopher Jones Date: Fri, 13 Nov 2009 23:57:53 +0000 Subject: [PATCH] add note about LOB & LONG cols git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@290726 c90b9560-bf6c-de11-be94-00142212c4b1 --- reference/oci8/functions/oci-set-prefetch.xml | 27 ++++++++++--------- 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/reference/oci8/functions/oci-set-prefetch.xml b/reference/oci8/functions/oci-set-prefetch.xml index c2a10d44d6..b2942566d5 100644 --- a/reference/oci8/functions/oci-set-prefetch.xml +++ b/reference/oci8/functions/oci-set-prefetch.xml @@ -34,17 +34,17 @@ re-executed statements or by other connections. - Call oci_set_prefetch before - calling oci_execute. + Call oci_set_prefetch before + calling oci_execute. - A tuning goal is to set the prefetch value to a reasonable size - for the network and database to handle. For queries returning a - very large number of rows, overall system efficiency might be - better if rows are retrieved from the database in several chunks - (i.e set the prefetch value smaller than the number of rows). - This allows the database to handle other users' statements while - your script is processing the current set of rows. + A tuning goal is to set the prefetch value to a reasonable size for + the network and database to handle. For queries returning a very + large number of rows, overall system efficiency might be better if + rows are retrieved from the database in several chunks (i.e set the + prefetch value smaller than the number of rows). This allows the + database to handle other users' statements while your script is + processing the current set of rows. Query prefetching was introduced in Oracle 8i. REF CURSOR @@ -52,9 +52,12 @@ linked with Oracle 11gR2 Client libraries and connected to 11gR2 or previous versions of the database. Nested cursor prefetching was introduced in Oracle 11gR2 and requires both the Oracle Client - libraries and the database to be version 11gR2. The prefetch value - is ignored and single-row fetches will be used when prefetching is - not supported. + libraries and the database to be version 11gR2. + + + Prefetching is not supported when queries contain LONG or LOB + columns. The prefetch value is ignored and single-row fetches will + be used in all the situations when prefetching is not supported.