Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
The database, keyspace, and table classes represent the replica-only
part of the objects after which they are named. Reading from a table
doesn't give you the full data, just the replica's view, and it is not
consistent since reconciliation is applied on the coordinator.
As a first step in acknowledging this, move the related files to
a replica/ subdirectory.
Fixes#7435
Adds an "eor" (end-of-record) column to cdc log. This is non-null only on
last-in-timestamp group rows, i.e. end of a singular source "event".
A client can use this as a shortcut to knowing whether or not he has a
full cdc "record" for a given source mutation (single row change).
Closes#7436
In some cases, tracking the state of processed rows inside `transformer`
is not needd at all. We don't need to do it if either:
- Preimage and postimage are disabled for the table,
- Only preimage is enabled and we are processing the last timestamp.
This commit disables updating the state in the cases listed above.
Introduces new methods to the change_processor interface that will cause
it to produce pre/postimage rows for requested clustering key, or for
static row.
Introduces logic in split.cc responsible for calling pre/postimage
methods of the change_processor interface. This does not have any effect
on generated CDC log mutations yet, because the transformer class has
empty implementations in place of those methods.
This allows for a more refined use of the transformer by the
for_each_change function (now named "process_changes_with_splitting).
The change_processor interface exposes two methods so far:
begin_timestamp, and process_change (previously named "transform").
By separating those two and exposing them, process_changes_with\
_splitting can cause the transformer to generate less CDC log mutations
- only one for each timestamp in the batch.
If a batch update is performed with a sequence of changes with a single
timestamp, they will now show up in CDC with a single timeuuid in the
`time` column, distinguished by different `batch_seq_no` values.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
`for_each_change` is like `split` but it doesn't return a vector of
mutations representing each change; instead, it takes as a parameter
a function which gets called on each mutation.
This reduced the memory usage and allows to preserve common context
when handling each change (will be useful in next commits).
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
The function checks if there are multiple timestamps and/or ttls inside
a mutation, which means separate changes should be created for this
mutation in CDC.
