… where InnoDB stored the first 768 bytes of variable length columns (BLOB, VARCHAR, TEXT) in the index record, and the remainder stored in overflow pages… be stored in it’s own page (less the 20 byte pointer stored in the index page). Based on our analysis 75% of the blobs stored in… the dynamic variable innodb_file_format=BARRACUDA (don’t forget to set it in my.cnf!): SET GLOBAL innodb_file_format=BARRACUDA; One…
Comment: Blob Storage in Innodb
February 17, 2010 By 13 Comments
… store blobs in DB rather as opposed to plain files in a filesystem? I agree with you in general, but there are applications where storing tons of files in a filesystem is bad. I ran into problems having many thousands (millions?) of files, where I…
Post: My Innodb Feature wishes
May 4, 2006 By 30 Comments
… other item with blobs – currently if I’m not mistaken blobs are stored each in its own “segment” which means having many blobs in the same row is going to be slow. For medium sized blobs… and promoting real one to unique. Tablespaces. To call “innodb_file_per_table” option tablespaces is a joke. It is better…
Post: Quickly preloading Innodb tables in the buffer pool
May 1, 2008 By 9 Comments
… go through .ibd file sequentially and inject pages in the buffer pool. This would make preload done using sequential file scan even if… tables) but it does not preload indexes in memory neither it does externally stored objects – BLOB and TEXT fields. If you would like… BLOB/TEXT externally stored columns you can use similar query: SELECT count(*) from tbl WHERE blob_col like “%0%”. Note if you preloading BLOB…
Comment: Cache Performance Comparison
August 10, 2006 By 74 Comments
… that storing it as plain files (as “/path/[chunkid]/[wordid]/vec.txtâ€? for example) would then hit the max open files limit which exists in many operating systems while storing it as blobs in mysql would only use 3 file handles (or how… gets something like 100.000 files in a single directory or more. A third thing is that storing in mysql you can have relations…
Comment: Cache Performance Comparison
August 10, 2006 By 74 Comments
Apachez, Absolutely. Storing data in the database will be slower than storing it on file as its adds up extra layer and extra processing… planty of copying especially for the blobs as in your case plus – if you use standard protocol blob will need to be unescaped… ether. This is why pretty much all major search engines store index data on hardware not database.
Post: Real-Life Use Case for "Barracuda" InnoDB File Format
April 23, 2008 By 11 Comments
… some information about possible benefits from using new InnoDB file format but in this post I’d like to share some real…,5 hours of conversion we’ve got 58Gb data file and 30% drop in our I/O load. This was related to… able to keep an entire PRIMARY index in memory (TEXT and BLOB fields are stored off-page in this format) and all our lookups…
Comment: Cache Performance Comparison
August 9, 2006 By 74 Comments
… assume based on above results that storing static data directly on the harddrive is better than storing it through mysql even if… engine which stores its chunked bitvectors as LZF compressed blobs in a table in mysql. Would it then be better to store those bitvectors in the… know its better to store say gif files in the filesystem than in mysql, but this case is like something in between (and I think…
Post: Bug#12704861
November 20, 2011 By 1 Comment
… redo log record for file extension in the current redo log format. What does this mean? If writing a BLOB causes the tablespace… BLOB pages in the mini-transaction of the B-tree operation. A further quirk is that BLOB pages are allocated from the same file… leaf pages of a mini-transaction allocated (nonfree=TRUE) before storing the BLOBs, or freed (nonfree=FALSE) before committing the mini-transaction…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…, if most of the pages in the extent have been accessed, and in an ascending order of the file address, then InnoDB schedules… InnoDB allocates for each blob outside of the page? HT: For each column that InnoDB needs to store ‘externally’, it allocates whole… to store locally a prefix of an indexed column. PZ: I think it is also very interesting question what happens for blobs…
