Co-authored-by: Georgy Moshkin <gmoshkin@picodata.io>

Kurdakov Alexander authored 6 months ago and Alexander Kurdakov committed 6 months ago

Previously some public lua functions in core-router.lua failed
returning nil instead of an error. As a result in a case of error
rust code treated it as success, but failed to pop expected results
from lua stack. So, instead of a real error user got lua reading
errors. Fixed.

Co-authored-by: Denis Smirnov <sd@picodata.io>

feat: add logic of correct local SQL generation for the case of asterisk (not in a view of references, but as "*")

fix: remove useless SubQuery nodes, fix logic of vtable columns naming (automatic indexes instead of names from local SQL metadata)

Arseniy Volynets authored 9 months ago and Arseniy Volynets committed 6 months ago

- For cacheable requests, we now send only cache required data needed to
execute the query if it is in the storage cache. If query is not in the
storage cache, storage returns empty result with flag indicating there
was a cache miss. Then coordinator sends the second round of requests to
replicasets where cache miss happened. It sends the full message there.
- Parameters for required message are now computed without compilation
to SyntaxPlan - Fixed parameter order in SyntaxPlan

Previously we cached only the leaf sub-trees of the IR plan under
the first level of motions. The problem was in temporary tables as
we used random names for them and dropped after usage (and invalidated
corresponding prepared statements as well). Now we use idempotent
names for temporary tables and truncate them after usage. It allows
us to keep prepared statements in the cache. One more thing: as we
use the same temporary table for multiple queries, we need to use
latch locks for the prepared statement cache. One day we'll switch
to more granular locks (mostly for vinyl spaces), but let's use
current approach for the start.

We also removed can_be_cached flag from the code. Only DQL uses VDBE
and needs caching, and all these queries can be cached. The only
exception are the queries with Local and LocalSegment motion policies
but only DML can have them. So, no need for this flag and let's make the
code cleaner.