html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,issue,performed_via_github_app
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1008166084,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1008166084,IC_kwDOCGYnMM48F2TE,536941,2022-01-08T22:32:47Z,2022-01-08T22:32:47Z,CONTRIBUTOR,or using “ pragma optimize”,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1008164786,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1008164786,IC_kwDOCGYnMM48F1-y,536941,2022-01-08T22:24:19Z,2022-01-08T22:24:19Z,CONTRIBUTOR,the out-of-date scenario you describe could be addressed by automatically adding an analyze to the insert or convert commands if they implicate an index,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1008164116,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1008164116,IC_kwDOCGYnMM48F10U,536941,2022-01-08T22:18:57Z,2022-01-08T22:18:57Z,CONTRIBUTOR,"the table with the query ran so bad was about 50k. 

i think the scenario should not be worse than no stats. 

i also did not know that sqlite was so different from postgres and needed an explicit analyze call.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1008163050,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1008163050,IC_kwDOCGYnMM48F1jq,9599,2022-01-08T22:10:51Z,2022-01-08T22:10:51Z,OWNER,"Is there a downside to having a `sqlite_stat1` table if it has wildly incorrect statistics in it?

Imagine the following sequence of events:

- User imports a few records, creating the table, using `sqlite-utils insert`
- User runs `sqlite-utils create-index ...` which also creates and populates the `sqlite_stat1` table
- User runs `insert` again to populate several million new records

The user now has a database file with several million records and a statistics table that is wildly out of date, having been populated when they only had a few.

Will this result in surprisingly bad query performance compared to it that statistics table did not exist at all?

If so, I lean much harder towards `ANALYZE` as a strictly opt-in optimization, maybe with the `--analyze` option added to `sqlite-utils insert` top to help users opt in to updating their statistics after running big inserts.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1008161965,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1008161965,IC_kwDOCGYnMM48F1St,536941,2022-01-08T22:02:56Z,2022-01-08T22:02:56Z,CONTRIBUTOR,"for options 2 and 3, i would worry about discoverablity. 

in other db’s it is not necessary to explicitly call analyze for most indices. ie for postgres

> The system regularly collects statistics on all of a table's columns. Newly-created non-expression indexes can immediately use these statistics to determine an index's usefulness.

i suppose i would propose raising a warning if the stats table is created that explains what is going on and informs users about a —no-analyze argument.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1008158357,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1008158357,IC_kwDOCGYnMM48F0aV,9599,2022-01-08T21:33:07Z,2022-01-08T21:33:07Z,OWNER,"The one thing that worries me a little bit about doing this by default is that it adds a surprising new table to the database - it may be confusing to users if they run `create-index` and their database suddenly has a new `sqlite_stat1` table, see https://github.com/simonw/sqlite-utils/issues/366#issuecomment-1008157132

Options here are:

- Do it anyway. People can tolerate a surprise table appearing when they create an index.
- Only run `ANALYZE` if the user says `sqlite-utils create-index ... --analyze`
- Use the `--analyze` option, but also automatically run `ANALYZE` if they create an index and the database they are working with already has a `sqlite_stat1` table

I'm currently leading towards that third option - @fgregg any thoughts?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1007643254,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1007643254,IC_kwDOCGYnMM48D2p2,9599,2022-01-07T18:37:56Z,2022-01-07T18:37:56Z,OWNER,Or I could leave off `--no-analyze` and tell people that if they want to add an index without running analyze they can execute the `CREATE INDEX` themselves.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1007642831,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1007642831,IC_kwDOCGYnMM48D2jP,9599,2022-01-07T18:37:18Z,2022-01-07T18:37:18Z,OWNER,"After implementing #366 I can make it so `sqlite-utils create-index` automatically runs `db.analyze(index_name)` afterwards, maybe with a `--no-analyze` option in case anyone wants to opt out of that for specific performance reasons.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1007636709,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1007636709,IC_kwDOCGYnMM48D1Dl,536941,2022-01-07T18:28:33Z,2022-01-07T18:29:43Z,CONTRIBUTOR,"i added an index to one table with sqlite-utils, and then a query that used to take about 1 second started taking hundreds of seconds. 

running analyze got me back to sub second speed.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1007634999,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1007634999,IC_kwDOCGYnMM48D0o3,9599,2022-01-07T18:26:22Z,2022-01-07T18:26:22Z,OWNER,"I've not used the `ANALYZE` feature in SQLite at all before. Should probably add Python library methods for it.

Annoyingly I use the word ""analyze"" to mean something else in the CLI - for these features:
- #207 
- #320","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,
https://github.com/simonw/sqlite-utils/issues/365#issuecomment-1007633376,https://api.github.com/repos/simonw/sqlite-utils/issues/365,1007633376,IC_kwDOCGYnMM48D0Pg,9599,2022-01-07T18:24:07Z,2022-01-07T18:24:07Z,OWNER,Relevant documentation: https://www.sqlite.org/lang_analyze.html,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096558279,