Select queries are not directly affected by replication, only
indirectly since replication requires resources and can increase lock
times for updates.
The things you mention seems to be more related to whether the query
cache has cached the result, different indexes, locking, and other issues.
Just my few cents,
Kandy Wong wrote:
> Is it true that the performance of running a query on a live replication
> master and slave has to be much slower than running a query on a static
> I've tried to run the following query on a replication master and it
> takes 1 min 13.76 sec to finish.
> SELECT *, ABS(timeA-1266143632) as distance FROM tableA WHERE timeA -
> 1266143632 <= 0 ORDER BY distance LIMIT 1;
> And if I run it on the replication slave, it takes 24.15 sec.
> But if I dump the whole database to another machine as static, it only
> takes 3.70 sec or even less to finish.
> The table has 386 columns and timeA is an index.
> Is there a way to improve the query or any other factors that would
> affect the performance?
Senior Software Engineer
Database Technology Group