introduce snapshot_ro isolation level (#11085)

[ssmike]

Changelog entry

Don't take locks in SnapshotRO

Changelog category

• Performance improvement

[github-actions]

⚪ 2024-11-05 07:42:08 UTC Pre-commit check for b7ab80a has started.
⚪ 2024-11-05 07:45:01 UTC Build linux-x86_64-relwithdebinfo is running...
🟢 2024-11-05 08:48:31 UTC Build successful.
⚪ 2024-11-05 08:48:47 UTC Tests are running...
🔴 2024-11-05 10:38:26 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
40285	35008	0	16	5219	42

🟢 2024-11-05 10:39:17 UTC ydbd size 8.2 GiB changed* by +208 Bytes, which is < 100.0 KiB vs stable-24-3: OK

ydbd size dash	stable-24-3: 66baaeb	merge: b7ab80a	diff	diff %
ydbd size	8 856 905 680 Bytes	8 856 905 888 Bytes	+208 Bytes	+0.000%
ydbd stripped size	483 653 544 Bytes	483 653 608 Bytes	+64 Bytes	+0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2024-11-05 07:44:11 UTC Pre-commit check for b7ab80a has started.
⚪ 2024-11-05 07:47:10 UTC Build linux-x86_64-release-clang14 is running...
🟢 2024-11-05 08:27:42 UTC Build successful.

[github-actions]

⚪ 2024-11-05 07:44:36 UTC Pre-commit check for b7ab80a has started.
⚪ 2024-11-05 07:47:35 UTC Build linux-x86_64-release-asan is running...
🟢 2024-11-05 08:31:02 UTC Build successful.
⚪ 2024-11-05 08:31:22 UTC Tests are running...
🔴 2024-11-05 10:42:13 UTC Some tests failed, follow the links below.

Test history | Test log

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
11726	11632	0	19	29	46

🟢 2024-11-05 10:43:05 UTC ydbd size 5.6 GiB changed* by +16 Bytes, which is < 100.0 KiB vs stable-24-3: OK

ydbd size dash	stable-24-3: 66baaeb	merge: b7ab80a	diff	diff %
ydbd size	5 990 435 688 Bytes	5 990 435 704 Bytes	+16 Bytes	+0.000%
ydbd stripped size	1 501 492 352 Bytes	1 501 492 288 Bytes	-64 Bytes	-0.000%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}