This PR refactors how we handle read consistency: does the `LanceTable`
class always pick up modifications to the table made by other instance
or processes. Users have three options they can set at the connection
level:
1. (Default) `read_consistency_interval=None` means it will not check at
all. Users can call `table.checkout_latest()` to manually check for
updates.
2. `read_consistency_interval=timedelta(0)` means **always** check for
updates, giving strong read consistency.
3. `read_consistency_interval=timedelta(seconds=20)` means check for
updates every 20 seconds. This is eventual consistency, a compromise
between the two options above.
## Table reference state
There is now an explicit difference between a `LanceTable` that tracks
the current version and one that is fixed at a historical version. We
now enforce that users cannot write if they have checked out an old
version. They are instructed to call `checkout_latest()` before calling
the write methods.
Since `conn.open_table()` doesn't have a parameter for version, users
will only get fixed references if they call `table.checkout()`.
The difference between these two can be seen in the repr: Table that are
fixed at a particular version will have a `version` displayed in the
repr. Otherwise, the version will not be shown.
```python
>>> table
LanceTable(connection=..., name="my_table")
>>> table.checkout(1)
>>> table
LanceTable(connection=..., name="my_table", version=1)
```
I decided to not create different classes for these states, because I
think we already have enough complexity with the Cloud vs OSS table
references.
Based on #812
@eddyxu added instructions for linting here:
7af213801a/python/README.md (L45-L50)
However, we had a lot of failures and weren't checking this in CI. This
PR fixes all lints and adds a check to CI to keep us in compliance with
the lints.
1. Support persistent embedding function so users can just search using
query string
2. Add fixed size list conversion for multiple vector columns
3. Add support for empty query (just apply select/where/limit).
4. Refactor and simplify some of the data prep code
---------
Co-authored-by: Chang She <chang@lancedb.com>
Co-authored-by: Weston Pace <weston.pace@gmail.com>
pypi does not allow packages to be uploaded that has a direct reference
for now we'll just ask the user to install tantivy separately
---------
Co-authored-by: Chang She <chang@lancedb.com>
