… TABLE CONVERT TO CHARACTER SET utf8; Does nothing except changes table/column encodings, but no actual content changes. So.. After this mysql thinks my table is utf8, I try the nr2 way mentioned in this blog: UPDATE table SET column=CONVERT(CONVERT(column USING binary) USING utf8) WHERE…
Post: Using CHAR keys for joins, how much is the overhead ?
June 18, 2007 By 18 Comments
…, KEY `i` (`i`), KEY `j` (`j`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 mysql> select sum(t1.i+t2.j+length(t2.c)+t1… Cache. So what if we convert i and j columns to varchar while sticking to utf8 character set which we had as… do is to convert Innodb table to latin1 character set. I was expected this to shorten some internal buffers MySQL has to…
Post: Extended EXPLAIN
July 24, 2006 By 9 Comments
…`.`sbtest`.`id` > 6) and (`test`.`sbtest`.`c` = _utf8‘a’) and (`test`.`sbtest`.`pad` = _utf8‘a’)) 1 row in set (0.00 sec… was fully quantified plus MySQL optimizer converted c=”a” and pad=c; to c=”a” and pad=”a”. MySQL optimizer could not however catch id>5 and id>6 can be converted just to id>6. Lets see another example: mysql…
Comment: MySQL Upgrade Webinar Questions Followup
June 28, 2012 By 7 Comments
… no difference as well as huge difference. The problem with utf8 is mainly when it comes to in memory temporary tables… a way to go. At the same time simply converting database to utf8 without application support on upgrade is a waste and… it as utf8 bad things can happen. The question is whenever moving to UTF8 is REQUIRED when you upgrade to MySQL 5.5…
Comment: Fixing column encoding mess in MySQL
January 26, 2011 By 32 Comments
… to do with it. The table is InnoDB, utf8, the column is utf8, the original data we imported may have been utf… MyISAM – it came out of Sql Server into MySQL, and may have been converted to utf-8 during that first import. I…-8 or ISO-8859-1), though if I display it converted to utf-8, it’s back to upside-down exclamation…
Post: Where does HandlerSocket really save you time?
March 16, 2011 By Leave a Comment
…(…) 200242.4660row_sel_store_mysql_rec 193472.3826btr_cur_search_to_nth_level 167012.0568row_sel_convert_mysql_key_to_innobase – Most…(…) 119342.7376JOIN::optimize() 101402.3261my_wc_mb_latin1 71521.6407my_utf8_uni 70921.6269Protocol::send_fields(List*, unsigned int) 65301.4980JOIN…
Post: Trying Archive Storage Engine
November 12, 2006 By 7 Comments
…NULL Update_time: NULL Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment:…-rw—- 1 mysql mysql 19 Nov 12 11:31 requests_061111.ARM -rw-rw—- 1 mysql mysql 984628803 Nov… big surprise as I got this table by converting MyISAM table rather than incremental insertions. I…
Comment: Converting Character Sets
March 18, 2009 By 22 Comments
… simple MODIFY can convert everything. 2. If the columns are declared as latin1 but the data are stored in utf8. This is quite common for applications created with MySQL < 4.1 or for applications which... mangle the data and conversion to binary and then to utf8 is necessary.
Post: What exactly is read_rnd_buffer_size
July 24, 2007 By 4 Comments
… which are being length can be converted to fixed size (basically everything but BLOB/TEXT) MySQL can use read_rnd_buffer to… accessed in pretty much random row pointer (typically physical) order. MySQL takes bunch of pointers from sort_buffer (just enough so… are long VARCHAR columns used – it takes only couple of UTF8 VARCHAR(255) to create a row which is longer than…
Post: Innodb row size limitation
April 7, 2011 By 12 Comments
…) ) Engine=InnoDB; Now you insert some test data into it: mysql> INSERT INTO example -> VALUES ( ->Â Â NULL, ->Â Â ‘First… possible that you hit this error after converting from a native language character set to utf8, as it can increase the size… application if you choose XML as format and you use MySQL‘s built in functions for handling this data. This approach…
