Before we were not updating the number of registers and cursors, which
meant that on a schema change the Program could now open an additional
cursor and we would not have space for it in the ProgramState, which
lead to the panic.
Closes#3002Closes#3034
Currently, when MVCC is enabled, every transaction mode supports
concurrent reads and writes, which makes it hard to adopt for existing
applications that use `BEGIN DEFERRED` or `BEGIN IMMEDIATE`.
Therefore, add support for `BEGIN CONCURRENT` transactions when MVCC is
enabled. The transaction mode allows multiple concurrent read/write
transactions that don't block each other, with conflicts resolved at
commit time. Furthermore, implement the correct semantics for `BEGIN
DEFERRED` and `BEGIN IMMEDIATE` by taking advantage of the pager level
write lock when transaction upgrades to write. This means that now
concurrent MVCC transactions are serialized against the legacy ones when
needed.
The implementation includes:
- Parser support for CONCURRENT keyword in BEGIN statements
- New Concurrent variant in TransactionMode to distinguish from regular
read/write transactions
- MVCC store tracking of exclusive transactions to support IMMEDIATE and
EXCLUSIVE modes alongside CONCURRENT
- Proper transaction state management for all transaction types in MVCC
This enables better concurrency for applications that can handle
optimistic concurrency control, while still supporting traditional
SQLite transaction semantics via IMMEDIATE and EXCLUSIVE modes.
The `run_once()` name is just a historical accident. Furthermore, it now
started to appear elsewhere as well, so let's just call it IO::step() as we
should have from the beginning.
If upgrade from read to write transaction fails, don't roll back the
transaction. Instead restore the transaction into its original state,
which allows deferred transactions that have not read anything to
restart automatically.
Fixes#2984
Using `usize` to compute file offsets caps us at ~16GB on 32-bit
systems. For example, with 4 KiB pages we can only address up to 1048576
pages; attempting the next page overflows a 32-bit usize and can wrap
the write offset, corrupting data. Switching our I/O APIs and offset
math to u64 avoids this overflow on 32-bit targets
Closes#2791
This patch brings a bunch of quality of life improvements to encryption:
1. Previously, we just let any string to be used as a key. I have
updated the `PRAGMA hexkey=''` to get the key in hex. I have also
renamed from `key`, because that will be used to get passphrase
2. Added `PRAGMA cipher` so that now users can select which cipher they
want to use (for now, either `aegis256` or `aes256gcm`)
3. We now set the encryption context when both cipher and key are set
I also updated tests to reflect this.
Reviewed-by: Preston Thorpe <preston@turso.tech>
Closes#2779
- transaction which was started with max_frame = 0 and max_frame_read_lock_index = 0
can write to the WAL and in this case it needs to read data back from WAL
- without cache spilling its hard to reproduce this issue for the turso-db now,
but I stumbled into this issue with sync-engine which do weird stuff with the WAL
which "simulates" cache spilling behaviour to some extent
Added `from_hex_string` which gets us `EncryptionKey` from a
hex string. Now we can use securely generated keys, like from openssl
$ openssl rand -hex 32
Implement very basic views using DBSP
This is just the bare minimum that I needed to convince myself that this
approach will work. The only views that we support are slices of the
main table: no aggregations, no joins, no projections.
* drop view is implemented.
* view population is implemented.
* deletes, inserts and updates are implemented.
much like indexes before, a flag must be passed to enable views.
Closes#2530
This is just the bare minimum that I needed to convince myself that this
approach will work. The only views that we support are slices of the
main table: no aggregations, no joins, no projections.
drop view is implemented.
view population is implemented.
deletes, inserts and updates are implemented.
much like indexes before, a flag must be passed to enable views.
Closes#1967
To support this I had to change how we did `epilogue` similarly to how
SQLite does it. SQLIte first declares a `beginWriteOperation` when some
statement is going to necessitate a Write Transaction. And as we now
need to pass the current schema cookie to `epilogue` it was easier to
call epilogue only in one location (like we do with prologue), and just
have each statement declare their intentions separately. This allows us
to not have to pass the Schema around just to do the epilogue. I believe
this is something that @jussisaurio would be interested in.
~Also had to disable the MVCC test, as it was extremely buggy for me.~
Just disabled reprepare statements for MVCC
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#2214
