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-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The user now has a database file with several million records and a statistics table that is wildly out of date, having been populated when they only had a few.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/366#issuecomment-1008158616,https://api.github.com/repos/simonw/sqlite-utils/issues/366,1008158616,IC_kwDOCGYnMM48F0eY,9599,2022-01-08T21:35:32Z,2022-01-08T21:35:32Z,OWNER,"Built a prototype in a branch, see #367.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096563265,
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/datasette/issues/1587#issuecomment-1008157998,https://api.github.com/repos/simonw/datasette/issues/1587,1008157998,IC_kwDOBm6k_c48F0Uu,9599,2022-01-08T21:29:54Z,2022-01-08T21:29:54Z,OWNER,Relevant code: https://github.com/simonw/datasette/blob/00a2895cd2dc42c63846216b36b2dc9f41170129/datasette/database.py#L339-L354,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1097040427,
https://github.com/simonw/datasette/issues/1587#issuecomment-1008157908,https://api.github.com/repos/simonw/datasette/issues/1587,1008157908,IC_kwDOBm6k_c48F0TU,9599,2022-01-08T21:29:06Z,2022-01-08T21:29:06Z,OWNER,"Depending on the SQLite version (and compile options) that ran `ANALYZE` these can be called:
- `sqlite_stat1`
- `sqlite_stat2`
- `sqlite_stat3`
- `sqlite_stat4`","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1097040427,
https://github.com/simonw/sqlite-utils/issues/366#issuecomment-1008157132,https://api.github.com/repos/simonw/sqlite-utils/issues/366,1008157132,IC_kwDOCGYnMM48F0HM,9599,2022-01-08T21:23:08Z,2022-01-08T21:25:05Z,OWNER,"Running `ANALYZE` creates a new visible table called `sqlite_stat1`: https://www.sqlite.org/fileformat.html#the_sqlite_stat1_table
This should be added to the default list of hidden tables in Datasette.
It looks something like this:
| tbl | idx | stat |
|---------------------------------|------------------------------------|-----------|
| _counts | sqlite_autoindex__counts_1 | 5 1 |
| global-power-plants_fts_config | global-power-plants_fts_config | 1 1 |
| global-power-plants_fts_docsize | | 33643 |
| global-power-plants_fts_idx | global-power-plants_fts_idx | 199 40 1 |
| global-power-plants_fts_data | | 136 |
| global-power-plants | ""global-power-plants_owner"" | 33643 4 |
| global-power-plants | ""global-power-plants_country_long"" | 33643 202 |
> In each such row, the sqlite_stat.stat column will be a string consisting of a list of integers followed by zero or more arguments. The first integer in this list is the approximate number of rows in the index. (The number of rows in the index is the same as the number of rows in the table, except for partial indexes.) The second integer is the approximate number of rows in the index that have the same value in the first column of the index. The third integer is the number number of rows in the index that have the same value for the first two columns. The N-th integer (for N>1) is the estimated average number of rows in the index which have the same value for the first N-1 columns. For a K-column index, there will be K+1 integers in the stat column. If the index is unique, then the last integer will be 1. ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1096563265,
https://github.com/simonw/sqlite-utils/issues/364#issuecomment-1008155916,https://api.github.com/repos/simonw/sqlite-utils/issues/364,1008155916,IC_kwDOCGYnMM48Fz0M,9599,2022-01-08T21:16:46Z,2022-01-08T21:16:46Z,OWNER,"No, `chunks()` seems to work OK in the test I just added.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1095570074,
https://github.com/simonw/sqlite-utils/issues/364#issuecomment-1008154873,https://api.github.com/repos/simonw/sqlite-utils/issues/364,1008154873,IC_kwDOCGYnMM48Fzj5,9599,2022-01-08T21:11:55Z,2022-01-08T21:11:55Z,OWNER,"I'm suspicious that the `chunks()` utility function may not be working correctly:
```pycon
In [10]: [list(d) for d in list(chunks('abc', 5))]
Out[10]: [['a'], ['b'], ['c']]
In [11]: [list(d) for d in list(chunks('abcdefghi', 5))]
Out[11]: [['a'], ['b'], ['c'], ['d'], ['e'], ['f'], ['g'], ['h'], ['i']]
In [12]: [list(d) for d in list(chunks('abcdefghi', 3))]
Out[12]: [['a'], ['b'], ['c'], ['d'], ['e'], ['f'], ['g'], ['h'], ['i']]
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1095570074,
https://github.com/simonw/sqlite-utils/issues/364#issuecomment-1008153586,https://api.github.com/repos/simonw/sqlite-utils/issues/364,1008153586,IC_kwDOCGYnMM48FzPy,9599,2022-01-08T21:06:15Z,2022-01-08T21:06:15Z,OWNER,"I added a print statement after `for query, params in queries_and_params` and confirmed that something in the code is waiting until 16 records are available to be inserted and then executing the inserts, even with `--batch-size 1`.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1095570074,
https://github.com/simonw/sqlite-utils/issues/364#issuecomment-1008151884,https://api.github.com/repos/simonw/sqlite-utils/issues/364,1008151884,IC_kwDOCGYnMM48Fy1M,9599,2022-01-08T20:59:21Z,2022-01-08T20:59:21Z,OWNER,"(That Heroku example doesn't record the timestamp, which limits its usefulness)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1095570074,
https://github.com/simonw/sqlite-utils/issues/364#issuecomment-1008143248,https://api.github.com/repos/simonw/sqlite-utils/issues/364,1008143248,IC_kwDOCGYnMM48FwuQ,9599,2022-01-08T20:34:12Z,2022-01-08T20:34:12Z,OWNER,Built that tool: https://github.com/simonw/stream-delay and https://pypi.org/project/stream-delay/,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1095570074,
https://github.com/simonw/sqlite-utils/issues/364#issuecomment-1008129841,https://api.github.com/repos/simonw/sqlite-utils/issues/364,1008129841,IC_kwDOCGYnMM48Ftcx,9599,2022-01-08T20:04:42Z,2022-01-08T20:04:42Z,OWNER,"It would be easier to test this if I had a utility for streaming out a file one line at a time.
A few recipes for this in https://superuser.com/questions/526242/cat-file-to-terminal-at-particular-speed-of-lines-per-second - I'm going to build a quick `stream-delay` tool though.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1095570074,