Rowsets are used in SQLite for two purposes:
1. for membership tests on a set of `i64`s,
2. for in-order iteration of a set of `i64`s,
Both in cases where we can just use rowids (which are `i64`) instead of building an entire ephemeral btree from a table's contents.
For example, in cases where a `DELETE FROM tbl WHERE ...` is performed on a table that has any `BEFORE DELETE` triggers, SQLite collects the table's rowids into a RowSet before actually performing the deletion. This is similar to how an UPDATE that modifies rowids (or the index used to iterate the UPDATE loop) will first collect the rows into an ephemeral index, and same with `INSERT INTO ... SELECT`.
This entire PR description was written by me - no AIs were harmed in the production of it. However, the code itself was mostly vibecoded using two agents in Cursor:
- Composer 1: given the SQLite opcode documentation and rowset.c source code, and asked to implement the VDBE instructions and the RowSet module.
- GPT-5: given the same SQLite docs and source code, and asked to review Composer 1's work and write feedback into a separate markdown file.
This loop was run for roughly 4-5 iterations, where each time GPT-5's feedback was given to Composer 1, until GPT-5 found nothing to comment anymore.
After this, I instructed Composer 1 to improve the documentation to be less stupid.
After that, I made a manual editing pass over the runtime code to e.g. change boolean flags to a `RowSetMode` enum to make clearer that the rowset has two distinct mutually exclusive purposes (membership tests and in-order iteration), plus cleaned up some other dumb shit and added comments.
I am still not sure if this saved time or not.
Depends on #3923 .
To have similar semantics to how `op_compare` works, we need to apply an
affinity to the values referenced in the `SeekKey` that is used for
seeking. This means keeping some affinity metadata for the `WhereTerms`
in the optimization phase, then before seeking, we emit an affinity
conversion. Had to dig deep in the sqlite code to understand this
better.
Unfortunately, we cannot have just one compare function to rule them all
here, as we have a specialized/optimized compare code to handle records
that have not yet been deserialized.
Closes#3707
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#3925
It seems that the build on macos arm is failing with `aegis` v0.9.0.
So, here I update `aegis`.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#3561
Depends on #3920
Moves some code around so it is easier to reuse and less cluttered in
`execute.rs`, and changes how `compare` works. Instead of mutating some
register, we now just return the possible `ValueRef` representation of
that affinity. This allows other parts of the codebase to reuse this
logic without needing to have an owned `Value` or a `&mut Register`
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#3923
Depends on #3919
Also change `op_compare` to reuse the same compare_immutable logic
First step to finish #2304
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#3920
Makes it easier to visualize what is related to Value and what is
related to opcodes. This will also facilitate in my next PR to
generalize certain function over `Value` and `ValueRef` as listed in
#2304Closes#3919
