josh radnor dating cobie smulders - Invalidating query cache entries replication

If the rare cases the query cache size would change so we get a false read the cache has either been cleared orprogress report: There is a confusion about the visibility and atomicity which can be expected.This makes it difficult to make a good decision without showing the concrete performance consequences to each decision.

invalidating query cache entries replication-63

This has the implication that the query cache cannot be enabled at runtime. After review, it may be pushed to the relevant source trees for release in the next version.

You can access the patch from: 2900 Kristofer Pettersson 2009-10-29 Bug#38551 query cache can still consume [very little] cpu time even when it is off.

When the query cache size is zero, all query cache functionallity should be skipped.

Since query_cache_size is protected from any changes by the barrier in Query_cache::resize() we can safely add a test at the begining of the invalidate* functions to avoid having mutexes locked when the query cache is ment to be disabled. After review, it may be pushed to the relevant source trees for release in the next version.

You can access the patch from: 2742 Kristofer Pettersson 2008-10-27 Bug#38551 query cache can still consume [very little] cpu time even when it is off.

By using the command line option --query_cache_type=0, the user can disable the query cache permanently and avoid taking the query cache mutex. After review, it may be pushed to the relevant source trees for release in the next version. After review, it may be pushed to the relevant source trees for release in the next version.

on the old non-Percona servers which caused the replication to halt until the cache was invalidated (Which took a lot of time). id=60696 We solved the issue by moving entirely to Percona My SQL server v5.5 which has the ability to disable Query Cache completely.

Description: Since the Query cache hurts some workloads, we turn if off by setting query_cache_size=0.

When the query cache is disabled, the server shouldn't attempt to take the query cache mutex.

By using the command line option --query_cache_type=0, the user can disable the query cache permanently and avoid taking the query cache mutex. After review, it may be pushed to the relevant source trees for release in the next version.

Query Cache::invalidate_table locks the query cache, invalidates the QC if query_cache_size 0, unlocks QC and returns.

Tags: , ,