Driving to work today, I had an epiphany thought, but wanted to see if anyone could prove my theory or not.
We currently have some tables that are approaching 1 BILLION rows (real Billion, with nine zeros, not that silly six zero version). Trying to do an "ALTER" on them to add a column can sometimes take hours. I'm wondering if we had the foresight to create the tables, and then tack on extra "dormant" columns of various common types, such as: future_uint int(10) unsigned null, future_int int(10) signed null, future_var varchar(255) null, Etc. So basically they'd be unused, then when we wanted a "new" column of that type, we would just "rename" the dormant one. I'm not sure if mySQL is smart enough to realize that if the schema definition for a column is identical, then it's just a simple rename, or if it treats any change the same and will still take hours to complete (if so, perhaps there's an optimization for you mysql developer team) Another option I considered, was is it possible to just go in with a hex editor and rename the field in the .frm file? Is there some kind of .frm editor available anywhere? r...@mypse:/var/lib/mysql/agis_core# hexdump -C country.frm 00001000 01 01 00 00 0a 00 00 00 02 00 01 00 00 00 01 80 |................| 00001010 02 00 00 12 00 02 00 ff 50 52 49 4d 41 52 59 ff |........PRIMARY.| 00001020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000013f0 00 00 00 00 00 00 00 00 00 00 00 00 06 00 49 6e |..............In| 00001400 6e 6f 44 42 00 00 00 00 00 00 00 00 00 00 00 00 |noDB............| 00001410 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00002150 04 00 0b 69 64 5f 63 6f 75 6e 74 72 79 00 05 00 |...id_country...| 00002160 05 69 73 6f 32 00 06 00 05 69 73 6f 33 00 07 00 |.iso2....iso3...| 00002170 0d 63 6f 75 6e 74 72 79 5f 6e 61 6d 65 00 04 0b |.country_name...| 00002180 05 05 00 02 00 00 12 00 0f 00 00 02 c0 00 00 05 |................| 00002190 05 06 06 00 04 00 00 00 80 00 00 00 fe c0 00 00 |................| 000021a0 06 05 09 09 00 0a 00 00 00 80 00 00 00 fe c0 00 |................| 000021b0 00 07 0d 42 fd 02 13 00 00 00 00 00 00 00 0f c0 |...B............| 000021c0 00 00 ff 69 64 5f 63 6f 75 6e 74 72 79 ff 69 73 |...future_var...| 000021d0 6f 32 ff 69 73 6f 33 ff 63 6f 75 6e 74 72 79 5f |...future_int...| -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
