Percona's MySQL & InnoDB performance and scalability blog
… in the article, this technique only works well for highly selective attributes. If attributes only have few distinct values (e.g… you don’t want to use this. Please see “Highly selective columns only” section for examples where it doesn’t work well…
… form. Q: Doesn’t the primary key solution for random selection only work when the IDs for movies are distributed uniformly… tradeoff of this solution is that it requires storing another column, and reinitializing the sequence after making certain insert/update/delete… matter, and it would have to match the order of columns in the index. Example: WHERE (last_name, first_name) = (‘Karwin…
… are also lagging behind). s2> select count(*) from t; +———-+ | count(*) | +———-+ | 2 | +———-+ # s1 is behind s1> select count(*) from t; +———-+ | count(*) | +———-+ |…c3ae-11e2-b986-0800272864ba:4 ? A ‘Last_Executed_GTID’ column would have been useful. In our case we can…
… the table id to find indexes of the table. mysql> select * from SYS_TABLES WHERE NAME=’sakila/actor’; +————–+—–+——–+——+——–+———+————–+——-+ | NAME | ID | N… how InnoDB uses `PREC` please let me know. mysql> select * from SYS_COLUMNS WHERE TABLE_ID=741; +———-+—–+————-+——-+———+——+——+ | TABLE_ID | POS | NAME | MTYPE…
…). Parallel applying would fail in case mixed CHAR and VARCHAR columns would be used in foreign key definitions. Bug fixed #1100496…). In case CREATE TABLE AS SELECT statement was running in parallel with the DDL statement on the selected table, in some cases…
… win of TokuDB is indexes. If you add multiple multi-column indexes the difference with InnoDB will be even more notable… allows multiple clustering indexes that give additional huge win on selects. We used TokuDB in the past (versions 3.x and…
… have a metric sh*tload of grants (on tables, on columns, …) that need an extra IP because you move from 127… simpler (and by extension, safer) to run (CREATE TABLE AS SELECT *, UPDATE host, INSERT) a few times than trying to recreate…
… be faster. 4. If you do queries on any other column, these could easily be quicker on a partitioned table, as… am really saying is that its not only about the ‘Selects‘ and Inserts, its also about what you do with the…
…, In theory you will see a significant increase in your Selects, as you will be querying on a smaller dataset. You… issuing queries against this table, but NOT using the id column. This could cause a longer running query, as the engine…
…: SELECT non_key_column FROM tbl WHERE key_column=x This query will roughly be evaluated in following steps, without MRR: SELECT key_column, pk_column…: SELECT key_column, pk_column FROM tbl WHERE key_column=x ORDER BY key_column (Note that secondary keys in InnoDB contain primary key columns) Buffer…
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