{"id":1869,"date":"2010-03-23T13:20:17","date_gmt":"2010-03-23T03:20:17","guid":{"rendered":"http:\/\/www.flamingspork.com\/blog\/?p=1869"},"modified":"2010-03-23T13:20:17","modified_gmt":"2010-03-23T03:20:17","slug":"on-tableidentifier-and-the-death-of-path-as-a-parameter-to-storageengines","status":"publish","type":"post","link":"https:\/\/www.flamingspork.com\/blog\/2010\/03\/23\/on-tableidentifier-and-the-death-of-path-as-a-parameter-to-storageengines\/","title":{"rendered":"on TableIdentifier (and the death of path as a parameter to StorageEngines)"},"content":{"rendered":"

As anybody who has ever implemented a Storage Engine for MySQL<\/a> will know, a bunch of the DDL calls got passed a parameter named “path”. This was a filesystem path. Depending on what platform you were running, it may contain \/ or \\ (and no, it’s not consistent on each platform). Add to that the difference if you were creating temporary tables (table name of #sql_somethingsomething) and the difference if you were one of the two (built in) engines that were able to be used for creating internal temporary tables (temp tables that are created during query execution that do not belong in a schema). Well… you had a bit of a mess.<\/p>\n

My earlier attempts involved splitting everything up into two strings: schema name and table name. This ended badly. The final architecture we decided on was to have an object passed around that would deal with various transformations (from what the user entered to what we can store on file systems, or to what temporary table maps to what unique name). This is TableIdentifier.<\/p>\n

Brian has been introducing it around the code for a while now, and we just got it to now most of the places where table names are passed to Storage Engines. This means that if you’re writing a Storage Engine that doesn’t just blindly store things in files, you can sensibly use the getSchemaName() and getTableName() methods to call your API.<\/p>\n","protected":false},"excerpt":{"rendered":"

As anybody who has ever implemented a Storage Engine for MySQL will know, a bunch of the DDL calls got passed a parameter named “path”. This was a filesystem path. Depending on what platform you were running, it may contain … 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":[75],"tags":[78,269,70,242,268],"class_list":["post-1869","post","type-post","status-publish","format-standard","hentry","category-drizzle-work-et-al","tag-api","tag-ddl","tag-drizzle","tag-storageengine","tag-tableidentifier"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5a6n8-u9","jetpack-related-posts":[{"id":1813,"url":"https:\/\/www.flamingspork.com\/blog\/2010\/03\/12\/writing-a-storage-engine-for-drizzle-part-2-create-table\/","url_meta":{"origin":1869,"position":0},"title":"Writing A Storage Engine for Drizzle, Part 2: CREATE TABLE","author":"Stewart Smith","date":"2010-03-12","format":false,"excerpt":"The DDL code paths for Drizzle are increasingly different from MySQL. For example, the embedded_innodb StorageEngine CREATE TABLE code path is completely different than what it would have to be for MySQL. This is because of a number of reasons, the primary one being that Drizzle uses a protobuf message\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":1655,"url":"https:\/\/www.flamingspork.com\/blog\/2009\/06\/09\/drizzle-pluggable-metadatastore-or-no-table-definition-file-on-disk\/","url_meta":{"origin":1869,"position":1},"title":"Drizzle pluggable MetadataStore (or: no table definition file on disk)","author":"Stewart Smith","date":"2009-06-09","format":false,"excerpt":"My code is shaping up rather nicely (see https:\/\/code.launchpad.net\/~stewart\/drizzle\/discovery) and I'm planning to submit a merge-request for it later today. I'm about to commit code that implements a MetadataStore for the ARCHIVE engine. This means that for ARCHIVE tables, you only have the .ARZ file on disk. The table definition\u2026","rel":"","context":"In "General"","block_context":{"text":"General","link":"https:\/\/www.flamingspork.com\/blog\/category\/general\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1874,"url":"https:\/\/www.flamingspork.com\/blog\/2010\/03\/30\/storing-the-table-message-in-embedded-innodb\/","url_meta":{"origin":1869,"position":2},"title":"Storing the table message in Embedded InnoDB","author":"Stewart Smith","date":"2010-03-30","format":false,"excerpt":"One of the exciting things[1] about working on a storage engine in Drizzle is that you get to manage your own metadata. When the database engine you're writing the storage engine interface for has a pretty complete data dictionary (e.g. Embedded InnoDB) you could just directly use it. At some\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":2329,"url":"https:\/\/www.flamingspork.com\/blog\/2011\/03\/23\/multi-tenancy-drizzle\/","url_meta":{"origin":1869,"position":3},"title":"Multi-tenancy Drizzle","author":"Stewart Smith","date":"2011-03-23","format":false,"excerpt":"My previous post focused on some of the problems of doing multi-tenant MySQL. One of the reasons why I started hacking on Drizzle was that the multi-tenancy options for MySQL just weren't very good (this is also the reason why I run my blog in a VM and not a\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":3234,"url":"https:\/\/www.flamingspork.com\/blog\/2013\/04\/04\/refactoring-internal-temporary-tables-another-stab-at-it\/","url_meta":{"origin":1869,"position":4},"title":"Refactoring Internal temporary tables (another stab at it)","author":"Stewart Smith","date":"2013-04-04","format":false,"excerpt":"A few weekends ago, I started to again look at the code in Drizzle for producing internal temporary tables. Basically, we have a few type of tables: Standard Temporary (from CREATE TEMPORARY TABLE) Temporary (from ALTER TABLE) Internal temporary (to help with query execution) If you're lucky enough to be\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":1274,"url":"https:\/\/www.flamingspork.com\/blog\/2008\/11\/26\/temporary-tables-in-any-engine\/","url_meta":{"origin":1869,"position":5},"title":"Temporary tables in any engine….","author":"Stewart Smith","date":"2008-11-26","format":false,"excerpt":"Well... nearly any engine. I have a plan forming in my head to add some hooks to engines to help with creating temporary tables (the ones created while executing a query, not ones created during ALTER TABLE). Currently, if you ALTER TABLE and we require a temporary table, it's still\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\/1869","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=1869"}],"version-history":[{"count":2,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/posts\/1869\/revisions"}],"predecessor-version":[{"id":1871,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/posts\/1869\/revisions\/1871"}],"wp:attachment":[{"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/media?parent=1869"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/categories?post=1869"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.flamingspork.com\/blog\/wp-json\/wp\/v2\/tags?post=1869"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}