It can be useful to match versions, since in some tables
(system.trace_log) there is only revision column.
P.S. came to this when was digging into stress reports from CI.
P.P.S. case insensitive by analogy with version().
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
- With this, invalid combinations of the FindAny/FindAnyIndex bools are
no longer possible and we can remove the corresponding check
- Also makes the instantiations more readable.
- This is not needed for non-const regexp array arguments (the
cardinality of arrays is fixed per column) but it cleans up the code
and runs the check only in functions which have restrictions on the
number of patterns.
- For functions using hyperscans, it was checked that the number of
regexes is < 2^32. Removed the check because I don't think anyone will
every specify 4 billion patterns.
- This is not needed for non-const regexp array arguments (the
cardinality of arrays is fixed per column) but it cleans up the code
and runs the check only in functions which have restrictions on the
number of patterns.
- For functions using hyperscans, it was checked that the number of
regexes is < 2^32. Removed the check because I don't think anyone will
every specify 4 billion patterns.
- The patterns are not used in hashing, there should not be a performance
impact when we use stuff from the standard library instead.
- added forgotten .reserve() in FunctionsMultiStringPosition.h
This commit migrates ClickHouse to Vectorscan. The first 10 min of
[0] explain the reasons for it.
(*) Addresses (but does not resolve) #38046
(*) Config parameter names (e.g. "max_hyperscan_regexp_length") are
preserved for compatibility. Likewise, error codes (e.g.
"ErrorCodes::HYPERSCAN_CANNOT_SCAN_TEXT") and function/class names (e.g.
"HyperscanDeleter") are preserved as vectorscan aims to be a drop-in
replacement.
[0] https://www.youtube.com/watch?v=KlZWmmflW6M
First part, updated most UTF8, hashing, memory and codecs. Except
utf8lower and upper, maybe a little later.
That includes huge amount of research with movemask dealing. Exact
details and blog post TBD.
