This PR adds `index_method` trait and implementation of toy sparse
vector index.
In order to make PR more lightweight - for now index methods are not
deeply integrated into the query planner and only necessary components
are added in order to make integration tests which uses `index_method`
API directly to work.
Primary changes introduced in this PR are:
1. `SymbolTable` extended with `index_methods` field and builtin
extensions populated with 2 native indices: `backing_btree` and
`toy_vector_sparse_ivf`
2. `Index` struct extended with `index_method` field which holds
`IndexMethodAttachment` constructed for the table with given parameters
from `IndexMethod` "factory" trait
The toy index implementation store inverted index pairs `(dimension,
rowid)` in the auxilary BTree index. This index uses special
`backing_btree` index_method which marked as `backing_btree: true` and
treated in a special way by the db core: this is real BTree index which
is not managed by the tursodb core and must be managed by index_method
created it (so it responsible for data population, creation, destruction
of this btree).
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#3846
- Add more statements per iteration
- Allow interactive transaction to contain multiple statements
- add VERBOSE flag to print all statements executed in a successful
iteration
This separates fuzz tests from integration tests so that you can run the
fast test cases with:
```
cargo test --test integration_tests
```
and the longer fuzz cases with:
```
cargo test --test fuzz_tests
```
