…: Using where; Using filesort 1 row in set (0.00 sec) mysql> explain select * from goods force index(cat_id) where cat… can be skewed) using filesort is better as otherwise very large portion of index may need to be scanned to find 10 matching… selective using index scan is much better idea. Until MySQL is able to handle this you will have to use force index hint…
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 27 Comments
… 20 or 30 bytes are being read. For Full Table Scan operation difference often would be larger. It is also interesting… also means sort can’t be done by index and extra sort pass (filesort) is required, which also makes MySQL to store… same amount of rows full table scan performs about 25 times better than accessing rows via index (for the case when data…
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
… runs normally – if you need to add/remove indexes and do other schema changes you probably would … time the replication thread was busy replicating events vs staying idle. Note you can speak about idle …0 117.75k 0 # 0% (5k) Filesort # 0% (5k) Full_join # 0% (7k) Full_scan # 0% (10k) Tmp_table # 0%…
