… used in textual protocol, which not only consumed time but also required extra memory consumption both on server and client. So in MySQL… conversion and copying Avoid SQL Injection Save memory on handling blobs There are also drawbacks and chewats of using prepared statements… not forget to close prepared statements – Many memory leaks reported in MySQL Server turned out to be prepare statements or cursors which…
Post: Adventures in archiving
February 11, 2013 By 16 Comments
… `compressed_data` ( `id` int(11) NOT NULL AUTO_INCREMENT, `dat` blob, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; CREATE TABLE… id desc limit 1; +———+ | id | +———+ | 1143883 | +———+ 1 row in set (2.04 sec) mysql> select id from compressed_row order by id desc limit 1; +———+ | id | +———+ | 1143883 | +———+ 1 row in set (0.00…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… points you need to attack the right query in the right way. But vanilla MySQL does have its limitations, it reports only… to enable logging atomically, not just for new connections as in MySQL. This is very helpful for measurement as otherwise we might…, so on-disk tables are probably being created because of blob columns being accessed by the query. So a quick fix…
Post: State of MySQL Market and will Replication live ?
April 9, 2008 By 29 Comments
… complex and too expensive to start with. In second half of 90s when MySQL appeared on the market many web applications were… to split the data in defined way so cross shard queries become a pain. Dealing with lag in MySQL Replication is another issue… scalable blog streaming to make it possible store large blobs such as images in the database efficiently. The other Wave is appliances…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
… obviously it is even easier if you have intent. In my opinion MySQL Security should be treated the following way – if you… keep max_prepared_stmt_count very low. Prepared Statements and Blob Data If you’re want to get memory consumed by… likely cause your MySQL server to run out of file descriptors. The same is true for Partitioned tables in MySQL 5.1 Disk…
Post: MySQL EXPLAIN limits and errors.
July 24, 2006 By 6 Comments
… only This is in works to be fixed in some of next version but it is so as of MySQL 5.0 The… long time In MySQL 5.0 with addition of greedy join the problem on looking at too many table join combinations in joins… well known – for example BLOB fields can’t work with in memory temporary table. The other thing – since MySQL 4.1 sorting can…
Comment: Cache Performance Comparison
August 10, 2006 By 74 Comments
… which exists in many operating systems while storing it as blobs in mysql would only use 3 file handles (or how many mysql uses per… something like 100.000 files in a single directory or more. A third thing is that storing in mysql you can have relations… compensate for the overhead that storing in mysql otherwise might be… Something I would like to see in this blog (if I can…
Post: Blob Storage in Innodb
February 9, 2010 By 13 Comments
… bytes of the BLOB may look strange, especially as MySQL internally has no optimizations to read portions of the blob – it is either… to implementing this in XtraDB 
So BLOB storage was not very efficient in REDUNDANT (MySQL 4.1 and below) and COMPACT (MySQL 5.0 and above) format and the fix comes with Innodb Plugin in…
Post: MySQL Blob Compression performance benefits
January 11, 2008 By 17 Comments
… of significant size in the table it often makes sense to keep it compressed. Unfortunately MySQL does not provide compressed BLOB/TEXT columns (I would really love to have COMPRESSED attribute for the BLOB/TEXT columns…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…. PZ: Cool. This is one of little known new features in MySQL 5.1 Q15: How frequently does Innodb fuzzy checkpointing is… InnoBD handles blobs/text fields (needs more info) According to the documentation, InnoDB put first 768 chars of each text/blob in the…_innodb.cc in 5.1: static MYSQL_SYSVAR_ULONG(thread_concurrency, srv_thread_concurrency, PLUGIN_VAR_RQCMDARG, “Helps in performance tuning in heavily concurrent…
