June 18, 2013

Post: Improved InnoDB fast index creation

… table without updating indexes took 18 seconds, and about the same time was spent on rebuilding the index using fast index creation. So we have 36 seconds in total which is about 1.7 times faster than updating indexes… impact on ALTER TABLE with the optimization disabled, and absolutely no effect on the optimized case, which resulted in an almost…

Post: Thinking about running OPTIMIZE on your Innodb Table ? Stop!

… ! Optimizing table straight away takes over 3 hours, while dropping indexes besides primary key, optimizing table and adding them back takes…, which is close than 20x speed difference and more compact index in the end. So if you’re considering running OPTIMIZE… with no indexes and bringing box down. You can also use this trick for ALTER TABLE which requires table rebuild. Dropping all indexes; doing…

Post: InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

… we’ve sorted this out, let’s drop and rebuild our FT index on the InnoDB table and try the above queries… rows are completely different; the scores are zero, which means “no match.” This looks promising, so let’s explore further. Again… KEY to an InnoDB table, be prepared for a table rebuild. Calculation of match score is completely different between the two…

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

… FTS_DOC_ID column, however, MySQL apparently has no problem with either of the following statements: mysql> … to get rid of them is to actually rebuild the table. -rw-rw—-. 1 mysql mysql 98304 … adding and dropping FT indexes, it’s entirely possible to DROP multiple FT indexes with InnoDB in the …

Post: Recovering Innodb table Corruption

… having data corrupted in secondary indexes, in which case simple OPTIMIZE TABLE could be enough to rebuild it, but it is much… see later. You may think why do not you simply rebuild table by using OPTIMIZE TABLE ? This is because Running in…_recs(page) > 0 || (level == 0 && page_get_page_no(page) == dict_index_get_page(index)) InnoDB: We intentionally generate a memory trap. InnoDB…

Post: Paul McCullagh answers your questions about PBXT

… like InnoDB, determines the recovery time. Does PBXT support clustered indexes? No, currently it does not. This is one of the original….  The table data page size does not require a rebuild because a page of records in the table is just… indexes, and can PBXT use MVCC for index scans? If you are using InnoDB in REPEATABLE READ mode, then there is essentially no

Post: Falcon Storage Engine Design Review

… not showing index sized in the release we tested it is hard to see how small indexes really are. [-] No “using index” Falcon always… but I’m not sure there they are now. [-] No Clustering Index support Unlike Innodb Falcon does not cluster data by Primary… about this feature, for example changing default value needs table rebuild even though for other storage engines it often could be…

Comment: Full text search for all MySQL Storage Engines

… not critical to keep the index 100% up-to-date, it’s better to cron it and rebuild at interval. In fact, MySQL documentation indicates it is much faster to rebuild sometimes as well. There… all the information together. Unfortunately, in MySQL, there are no expression-based indexes, but I’m not 100% sure that would work…

Post: Hacking to make ALTER TABLE online for certain changes

Suppose you want to remove auto_increment from 100G table. No matter if it’s InnoDB or MyISAM, you’d usually… wait hours for table rebuild to complete. If you’re unlucky i.e. you have a lot of indexes and not too… altering huge InnoDB tables and huge tables take time to rebuild. Disclaimer: try this at your own risk. It worked for…

Post: MySQL EXPLAIN limits and errors.

… executed – will in add index live as it can now do on Cluster ? Is it expected to rebuild index by sort of key… than compose full rows by reading data from other tables. No information about using disk for sort or temporary tables MySQL… uncached table by random index values (or even range) may be perfoming at some 100 rows/sec. No info about functions cost…