- Made the code around snapshot isolation more ergonomic with each
connections having its own transaction state. Also when shadowing, we
pass a ShadowTablesMut object that dynamically uses the committed tables
or the connection tables depending on the transaction state.
- added begin concurrent transaction before every property when mvcc is
enabled (this is just so we can have some mvcc code be tested using the
simulator under Begin Concurrent, I have not yet implemented the logic
to have concurrent transactions in the simulator)
- some small enhancements to shrinking
TODOs
- have proper logic to have concurrent transactions without WriteWrite
conflicts. This means when generating the plans we need to make sure
that we do not generate rows that will conflict with rows in other
transactions. This is slightly more powerful than what we do in the
fuzzer, as we just have `WriteWriteConflict` as an acceptable error
there. By baking this `NoConflict` approach to the simulator, we can
continuously test the what does not trigger a WriteWriteConflict and
snapshot isolation.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#3226
Add a `Once` object to uphold this property. We cannot use the OnceLock
to dictate this, because if we set the OnceLock before actually calling
the callback, there is a moment in time where we will have an incorrect
transient state. This change ensures we atomically call the callback and
then set the OnceLock
Should fix#3217Closes#3217Closes#3237
UNION queries, while useful on their own, are a cornerstone of recursive
CTEs.
This PR implements:
* the merge operator, required to merge both sides of a union query.
* the circuitry necessary to issue the Merge operator.
* extraction of tables mentioned in union and CTE expressions, so we can
correctly populate tables that contain them.
Closes#3234
We currently don't handle non equality, but end up just returning a
bogus result. Let's parse error.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#3232
This PR improves sync and database bindings for browser
List of changes:
- For node and browser database now run on main thread and only IO work
offloaded to the worker (web worker in browser)
- Simple locks are implemented for database access externally in order
to guard access to the same connection (when request is executed async -
main thread can try to start another request concurrently)
- parking_lot in the Wal replaced by spin-wait (by invoking
`parking_lot.try_read/try_write`) for WASM target because browser can't
park main thread
- js sync reworked in order to support few engine options
(`longPollTimeoutMs`) and introduce external locking which properly
guards concurrent access of sync methods
Closes#3218
The Merge operator is a stateless operator that merges two deltas.
There are two modes: Distinct, where we merge together values that
are the same, and All, where we preserve all values. We use the rowid of
the hashable row to guarantee that: In Distinct mode, the rowid is set
to 0 in both sides. If they values are the same, they will hash to the
same thing. For All, the rowids are different.
The merge operator is used for the UNION statement, which is a
cornerstone of Recursive CTEs.
The population code extracts table information from the select statement
so it can populate the materialized view. But the code, as written
today, is naive. It doesn't capture table information correctly if there
is more than one select statement (such in the case of a union query).
Previously we were rewriting/traversing the AST in a couple different
places, each of these added kinda ad-hoc as we needed them. This
attempts to do the binding of column references as well as the rewriting
of anonymous `Expr::Variable` -> `__param_N` that we use to maintain the
order of bound variables, also normalizes the Qualified Name's.
Also we previously weren't accepting Variable (or at least they wouldn't
work) in places like `LIMIT ? OFFSET ?`, which this PR adds.
I kinda want to keep refactoring translation a bit, and try to break
plan building up into more easy-to-digest chunks.. but I will resist the
urge right now as it's definitely not high priority pre-beta
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#3210
I don't want to even think about the complexity involved in making sure
that materialized views are still sane after the base table(s) are
altered.
Reviewed-by: Preston Thorpe <preston@turso.tech>
Closes#3223
This PR introduces the final major operator: the JOIN operator.
Many things need to be fixed before we can properly support them, and we
handle those. In particular, JOINs always generate qualified column
statements, but we were not handling them correctly at all in the
operators. Not a problem for linear circuits, but fatal for JOINs.
The operator.rs file also becomes incredibly complex with not one, but
two stateful operator. So it is now broken apart.
Closes#3207
