{"id":1409,"date":"2009-02-20T13:13:33","date_gmt":"2009-02-20T03:13:33","guid":{"rendered":"http:\/\/www.flamingspork.com\/blog\/?p=1409"},"modified":"2014-10-08T09:13:29","modified_gmt":"2014-10-07T23:13:29","slug":"improving-the-storage-engine-api","status":"publish","type":"post","link":"https:\/\/www.flamingspork.com\/blog\/2009\/02\/20\/improving-the-storage-engine-api\/","title":{"rendered":"Improving the Storage Engine “API”"},"content":{"rendered":"

I increasingly enclose the API part of “Storage Engine API” in quotes as it does score a rather large number on the API Design Rusty levels<\/a> (Coined by Rusty Russell<\/a>). I give it a 15 (out of 18. lower is better) in this case “The obvious use is wrong”.<\/p>\n

The ideas is that your handler gets called to write a row (the amazingly named handler::write_row()). It’s passed a buffer which is the row to be stored. An engine that uses the MySQL row format (lets say, ARCHIVE) will simply pack the row and write it out.<\/p>\n

Unless there is a TIMESTAMP field with auto set on insert. Up until now (and still now in MySQL) the engine had to check if this was the case and make sure the timestamp field was updated.<\/p>\n

To remove this particular bonghit is actually a really small patch, which Jay recently got merged:<\/p>\n

~drizzle-developers\/drizzle\/development : revision 873.1.16<\/a><\/p>\n

Hopefully somebody does this soon for MySQL as well.<\/p>\n","protected":false},"excerpt":{"rendered":"

I increasingly enclose the API part of “Storage Engine API” in quotes as it does score a rather large number on the API Design Rusty levels (Coined by Rusty Russell). I give it a 15 (out of 18. lower is … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[76,75,14],"tags":[70,628,80],"class_list":["post-1409","post","type-post","status-publish","format-standard","hentry","category-code","category-drizzle-work-et-al","category-mysql","tag-drizzle","tag-mysql","tag-storage-engine-api"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5a6n8-mJ","jetpack-related-posts":[{"id":1931,"url":"https:\/\/www.flamingspork.com\/blog\/2010\/05\/26\/blobs-in-the-drizzlemysql-storage-engine-api\/","url_meta":{"origin":1409,"position":0},"title":"BLOBS in the Drizzle\/MySQL Storage Engine API","author":"Stewart Smith","date":"2010-05-26","format":false,"excerpt":"Another (AFAIK) undocumented part of the Storage Engine API: We all know what a normal row looks like in Drizzle\/MySQL row format (a NULL bitmap and then column data): Nothing that special. It's a fixed sized buffer, Field objects reference into it, you read out of it and write the\u2026","rel":"","context":"In "drizzle"","block_context":{"text":"drizzle","link":"https:\/\/www.flamingspork.com\/blog\/category\/work-et-al\/drizzle-work-et-al\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.flamingspork.com\/blog\/wp-content\/uploads\/2010\/05\/rect28161-300x67.png?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":1879,"url":"https:\/\/www.flamingspork.com\/blog\/2010\/05\/24\/using-the-row-buffer-in-drizzle-and-mysql\/","url_meta":{"origin":1409,"position":1},"title":"Using the row buffer in Drizzle (and MySQL)","author":"Stewart Smith","date":"2010-05-24","format":false,"excerpt":"Here's another bit of the API you may need to use in your storage engine (it also seems to be a rather unknown. I believe the only place where this has really been documented is ha_ndbcluster.cc, so here goes.... Drizzle (through inheritance from MySQL) has its own (in memory) row\u2026","rel":"","context":"In "drizzle"","block_context":{"text":"drizzle","link":"https:\/\/www.flamingspork.com\/blog\/category\/work-et-al\/drizzle-work-et-al\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.flamingspork.com\/blog\/wp-content\/uploads\/2010\/04\/row-300x85.png?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":2168,"url":"https:\/\/www.flamingspork.com\/blog\/2010\/10\/25\/storage-engine-api-state-graph\/","url_meta":{"origin":1409,"position":2},"title":"Storage Engine API state graph","author":"Stewart Smith","date":"2010-10-25","format":false,"excerpt":"Drizzle still has a number of quirks inherited from the MySQL Storage Engine API (e.g. BLOBs, row buffer, CREATE SELECT and lack of DDL transaction boundaries, key tuple format). One of the things we fixed a long time ago was to have proper methods for StorageEngines to be called for:\u2026","rel":"","context":"In "code"","block_context":{"text":"code","link":"https:\/\/www.flamingspork.com\/blog\/category\/code\/"},"img":{"alt_text":"State transitions for a transaction. Transaction can be empty OR have one or more statements","src":"https:\/\/i0.wp.com\/www.flamingspork.com\/blog\/wp-content\/uploads\/2010\/10\/edge30-300x163.png?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":1876,"url":"https:\/\/www.flamingspork.com\/blog\/2010\/04\/02\/the-drizzle-and-mysql-key-tuple-format\/","url_meta":{"origin":1409,"position":3},"title":"The Drizzle (and MySQL) Key tuple format","author":"Stewart Smith","date":"2010-04-02","format":false,"excerpt":"Here's something that's not really documented anywhere (unless you count ha_innodb.cc as a source of server documentation). You may have some idea about the MySQL\/Drizzle row buffer format. This is passed around the storage engine interface: in for write_row and update_row and out for the various scan and index read\u2026","rel":"","context":"In "drizzle"","block_context":{"text":"drizzle","link":"https:\/\/www.flamingspork.com\/blog\/category\/work-et-al\/drizzle-work-et-al\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":3345,"url":"https:\/\/www.flamingspork.com\/blog\/2013\/05\/23\/mysql-vs-drizzle-plugin-api\/","url_meta":{"origin":1409,"position":4},"title":"MySQL vs Drizzle plugin APIs","author":"Stewart Smith","date":"2013-05-23","format":false,"excerpt":"There's a big difference in how plugins are treated in MySQL and how they are treated in Drizzle. The MySQL way has been to create a C API in front of the C++-like (I call it C- as it manages to take the worst of both worlds) internal \"API\". The\u2026","rel":"","context":"In "code"","block_context":{"text":"code","link":"https:\/\/www.flamingspork.com\/blog\/category\/code\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1903,"url":"https:\/\/www.flamingspork.com\/blog\/2010\/04\/21\/storage-engine-api-write_row-create-select-and-ddl\/","url_meta":{"origin":1409,"position":5},"title":"Storage Engine API: write_row, CREATE SELECT and DDL","author":"Stewart Smith","date":"2010-04-21","format":false,"excerpt":"(this probably applies exactly the same for MySQL and Drizzle... but I'm just speaking about current Drizzle here) In my current merge request for the embedded-innodb\u00ef\u00bb\u00bf-create-select-transaction-arrgh branch (also see this specific revision), you'll notice an odd hoop that we have to jump through to make CREATE SELECT statements work with\u2026","rel":"","context":"In "drizzle"","block_context":{"text":"drizzle","link":"https:\/\/www.flamingspork.com\/blog\/category\/work-et-al\/drizzle-work-et-al\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/posts\/1409","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/comments?post=1409"}],"version-history":[{"count":5,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/posts\/1409\/revisions"}],"predecessor-version":[{"id":3821,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/posts\/1409\/revisions\/3821"}],"wp:attachment":[{"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/media?parent=1409"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/categories?post=1409"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/tags?post=1409"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}