Currently, when two cells have the same write timestamp
and both are alive or expiring, we compare their value first,
before checking if either of them is expiring
and if both are expiring, comparing their expiration time
and ttl value to determine which of them will expire
later or was written later.
This was based on an early version of Cassandra.
However, the Cassandra implementation rightfully changed in
e225c88a65 ([CASSANDRA-14592](https://issues.apache.org/jira/browse/CASSANDRA-14592)),
where the cell expiration is considered before the cell value.
To summarize, the motivation for this change is three fold:
1. Cassandra compatibility
2. Prevent an edge case where a null value is returned by select query when an expired cell has a larger value than a cell with later expiration.
3. A generalization of the above: value-based reconciliation may cause select query to return a mixture of upserts, if multiple upserts use the same timeastamp but have different expiration times. If the cell value is considered before expiration, the select result may contain cells from different inserts, while reconciling based the expiration times will choose cells consistently from either upserts, as all cells in the respective upsert will carry the same expiration time.
\Fixes scylladb/scylladb#14182
Also, this series:
- updates dml documentation
- updates internal documentation
- updates and adds unit tests and cql pytest reproducing #14182
\Closes scylladb/scylladb#14183
* github.com:scylladb/scylladb:
docs: dml: add update ordering section
cql-pytest: test_using_timestamp: add tests for rewrites using same timestamp
mutation_partition: compare_row_marker_for_merge: consider ttl in case expiry is the same
atomic_cell: compare_atomic_cell_for_merge: update and add documentation
compare_atomic_cell_for_merge: compare value last for live cells
mutation_test: test_cell_ordering: improve debuggability
(cherry picked from commit 87b4606cd6)
Closes#14651
Fix https://github.com/scylladb/scylla-doc-issues/issues/816
Fix https://github.com/scylladb/scylla-docs/issues/1613
This PR fixes the CQL version in the Interfaces page, so that it is the same as in other places across the docs and in sync with the version reported by the ScyllaDB (see https://github.com/scylladb/scylla-doc-issues/issues/816#issuecomment-1173878487).
To make sure the same CQL version is used across the docs, we should use the `|cql-version| `variable rather than hardcode the version number on several pages.
The variable is specified in the conf.py file:
```
rst_prolog = """
.. |cql-version| replace:: 3.3.1
"""
```
Closes#11320
* github.com:scylladb/scylladb:
doc: add the Cassandra version on which the tools are based
doc: fix the version number
doc: update the Enterprise version where the ME format was introduced
doc: add the ME format to the Cassandar Compatibility page
doc: replace Scylla with ScyllaDB
doc: rewrite the Interfaces table to the new format to include more information about CQL support
doc: remove the CQL version from pages other than Cassandra compatibility
doc: fix the CQL version in the Interfaces table
(cherry picked from commit ee606a5d52)
Release 5.1. introduced a new CQL extension that applies to the CREATE TABLE and ALTER TABLE statements. The ScyllaDB-specific extensions are described on a separate page, so the CREATE TABLE and ALTER TABLE should include links to that page and section.
Note: CQL extensions are described with Markdown, while the Data Definition page is RST. Currently, there's no way to link from an RST page to an MD subsection (using a section heading or anchor), so a URL is used as a temporary solution.
Related: https://github.com/scylladb/scylladb/pull/9810Closes#12070
* github.com:scylladb/scylladb:
doc: move the info about per-partition rate limit for the ALTER TABLE statemet from the paragraph to the list
doc: add the links to the per-partition rate limit extention to the CREATE TABLE and ALTER TABLE sections
(cherry picked from commit 6e9f739f19)
It was pointed out to me that our description of the synchronous_updates
materialized-view option does not make it clear enough what is the
default setting, or why a user might want to use this option.
This patch changes the description to (I hope) better address these
issues.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#11404
* github.com:scylladb/scylladb:
doc: cql-extensions.md: replace "Scylla" by "ScyllaDB"
doc: cql-extensions.md: improve description of synchronous views
(cherry picked from commit b9fc504fb2)
This PR is V2 of the[ PR created by @psarna.](https://github.com/scylladb/scylladb/pull/11560).
I have:
- copied the content.
- applied the suggestions left by @nyh.
- made minor improvements, such as replacing "Scylla" with "ScyllaDB", fixing punctuation, and fixing the RST syntax.
Fixes https://github.com/scylladb/scylladb/issues/11378Closes#11984
* github.com:scylladb/scylladb:
doc: label user-defined functions as Experimental
doc: restore the note for the Count function (removed by mistatke)
doc: document user defined functions (UDFs)
(cherry picked from commit 7cbb0b98bb)
Fix https://github.com/scylladb/scylladb/issues/11373
- Updated the information on the "Counting all rows in a table is slow" page.
- Added COUNT to the list of selectors of the SELECT statement (somehow it was missing).
- Added the note to the description of the COUNT() function with a link to the KB page for troubleshooting if necessary. This will allow the users to easily find the KB page.
Closes#11417
* github.com:scylladb/scylladb:
doc: add a comment to remove the note in version 5.1
doc: update the information on the Countng all rows page and add the recommendation to upgrade ScyllaDB
doc: add a note to the description of COUNT with a reference to the KB article
doc: add COUNT to the list of acceptable selectors of the SELECT statement
(cherry picked from commit 22bb35e2cb)
