From 5068d49cf748dbf9fbe08ff5d7409fe21b54399c Mon Sep 17 00:00:00 2001 From: Johan Wikman Date: Wed, 25 Oct 2017 10:08:36 +0300 Subject: [PATCH] MXS-1474 Update cache documentation --- Documentation/Filters/Cache.md | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/Documentation/Filters/Cache.md b/Documentation/Filters/Cache.md index 15adb28f1..0310d077b 100644 --- a/Documentation/Filters/Cache.md +++ b/Documentation/Filters/Cache.md @@ -22,6 +22,10 @@ been started with `BEGIN`, `START TRANSACTION` or `START TRANSACTION READ WRITE`, then the cache will be used and populated until the first `UPDATE`, `INSERT` or `DELETE` statement is encountered. +That is, in default mode the cache effectively causes the system to behave +as if the _isolation level_ would be `READ COMMITTED`, irrespective of what +the isolation level of the backends actually is. + The default behaviour can be altered using the configuration parameter [cache_inside_transactions](#cache_inside_transactions). @@ -264,11 +268,9 @@ are active transactions: The cache will be populated if the transaction is explicitly read only or if no non-SELECT statement has been encounted. * `read_only_transactions`: The cache will be used and populated inside - _explicitly_ read-only transactions. If the transaction is not explicitly - read only, the cache will be populated (but not used) until the first - non-SELECT statement. + _explicitly_ read-only transactions. * `all_transactions`: The cache will be used and populated inside - explicitly read-only transactions. Inside transactions that are not + _explicitly_ read-only transactions. Inside transactions that are not explicitly read-only, the cache will be used and populated _until_ the first non-SELECT statement. ```