When looking at the directory that stores all the files for a database, I see my table that has a TEXT column. I see "tbl.frm","tbl.myi","tbl.myd". This is the same for tables that do not have TEXT columns, so I can rule out separate files as a possible storage method for TEXT. There are also no extra files in the directory which could have been used as a generic storage area for TEXT data. Since we already know the row size is not increased by the size of the TEXT column, only by the size of the pointer used to point to the location of the TEXT (1,2,3 or 4 bytes). This means the TEXT space allocation occurs when the row is inserted and is placed in the *.myd file at some proprietary location and method. And the relative pointer to this area is placed in the TEXT field of the original containing row.
Ed -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday, June 17, 2004 8:36 AM To: emierzwa Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: RE: Where are BLOBs / TEXTs stored? I am curious about this, too. However, I don't think that you answer the original question. Are BLOBs stored as separate files, one file per object? Are they combined into a single large BLOB file? are they aggregated into several medium sized files? Answering "where are they stored on the disk" may be a better response as the docs state that they are not stored in the MyISAM table itself but as "separate objects" (which means what, exactly?) Shawn Green Database Administrator Unimin Corporation - Spruce Pine [EMAIL PROTECTED] om To: <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]> cc: 06/17/2004 09:17 Fax to: AM Subject: RE: Where are BLOBs / TEXTs stored? Found this at http://dev.mysql.com/doc/mysql/en/BLOB.html, basically it's not stored in the table row along with any other columns in the same row. 12.4.2 The BLOB and TEXT Types Each BLOB or TEXT value is represented internally by a separately allocated object. This is in contrast to all other column types, for which storage is allocated once per column when the table is opened. Ed -----Original Message----- From: Luis R. Rodriguez [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 16, 2004 6:37 PM To: [EMAIL PROTECTED] Subject: Where are BLOBs / TEXTs stored? [ Please CC me ] Hi, http://dev.mysql.com/doc/mysql/en/Storage_requirements.html Page says: --- "The maximum size of a row in a MyISAM table is 65,534 bytes. Each BLOB and TEXT column accounts for only five to nine bytes toward this size." --- Question: So where are BLOBs and TEXTs entries stored? Luis -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
