Change Details

This is the task for the schema change project documented on the wiki at [[https://www.mediawiki.org/wiki/User:Brion_VIBBER/Compacting_the_revision_table_round_2|User:Brion VIBBER/Compacting the revision table round 2]]. Part of the description is copied below. Per ongoing discussion in ArchCom and at WikiDev17 about performance, future requirements, and future-proofing for table size it's proposed to do a major overhaul of the revision table, combining the following improvements: * Normalization of frequently duplicated data to separate tables, reducing the dupe strings to integer keys * Separation of content-specific from general-revision metadata to support: * Multi-content revisions allowing for storing of multiple content blobs per revision -- not related to compaction, but of great interest for structured data additions planned for multimedia and articles * general reduction in revision table width / on-disk size will make schema changes easier in future * trying to avoid inconsistencies in live index deployments * ideally all indexes should fit on all servers, making it easier to switch database backend around in production ---- The specific changes and associated Wikimedia production tasks involved here are: * Dropping `rev_comment`, adding `rev_comment_id`. (T166733, T215466) [x] Ready to go! * Dropping `rev_user` and `rev_user_text`, adding `rev_actor`. (T188327, T215466) [x] Ready to go! * Dropping `rev_text_id`, `rev_content_model`, and `rev_content_format`. (T184615, T238966) [x] Ready to go! * Fixing the type of `rev_timestamp` on old wikis to match tables.sql. (P8433) [x] Ready to go!

This is the task for the schema change project documented on the wiki at [[https://www.mediawiki.org/wiki/User:Brion_VIBBER/Compacting_the_revision_table_round_2|User:Brion VIBBER/Compacting the revision table round 2]]. Part of the description is copied below. Per ongoing discussion in ArchCom and at WikiDev17 about performance, future requirements, and future-proofing for table size it's proposed to do a major overhaul of the revision table, combining the following improvements: * Normalization of frequently duplicated data to separate tables, reducing the dupe strings to integer keys * Separation of content-specific from general-revision metadata to support: * Multi-content revisions allowing for storing of multiple content blobs per revision -- not related to compaction, but of great interest for structured data additions planned for multimedia and articles * general reduction in revision table width / on-disk size will make schema changes easier in future * trying to avoid inconsistencies in live index deployments * ideally all indexes should fit on all servers, making it easier to switch database backend around in production ---- The specific changes and associated Wikimedia production tasks involved here are: * Dropping `rev_comment`, adding `rev_comment_id`. (T166733, T215466) [x] Ready to go! * Dropping `rev_user` and `rev_user_text`, adding `rev_actor`. (T188327, T215466) [x] Ready to go! * Dropping `rev_text_id`, `rev_content_model`, and `rev_content_format`. (T238958, T238966) [x] Ready to go! * Fixing the type of `rev_timestamp` on old wikis to match tables.sql. (P8433) [x] Ready to go!

This is the task for the schema change project documented on the wiki at [[https://www.mediawiki.org/wiki/User:Brion_VIBBER/Compacting_the_revision_table_round_2|User:Brion VIBBER/Compacting the revision table round 2]]. Part of the description is copied below. Per ongoing discussion in ArchCom and at WikiDev17 about performance, future requirements, and future-proofing for table size it's proposed to do a major overhaul of the revision table, combining the following improvements: * Normalization of frequently duplicated data to separate tables, reducing the dupe strings to integer keys * Separation of content-specific from general-revision metadata to support: * Multi-content revisions allowing for storing of multiple content blobs per revision -- not related to compaction, but of great interest for structured data additions planned for multimedia and articles * general reduction in revision table width / on-disk size will make schema changes easier in future * trying to avoid inconsistencies in live index deployments * ideally all indexes should fit on all servers, making it easier to switch database backend around in production ---- The specific changes and associated Wikimedia production tasks involved here are: * Dropping `rev_comment`, adding `rev_comment_id`. (T166733, T215466) [x] Ready to go! * Dropping `rev_user` and `rev_user_text`, adding `rev_actor`. (T188327, T215466) [x] Ready to go! * Dropping `rev_text_id`, `rev_content_model`, and `rev_content_format`. (T184615T238958, T238966) [x] Ready to go! * Fixing the type of `rev_timestamp` on old wikis to match tables.sql. (P8433) [x] Ready to go!