- We didn't traverse output during subtree
traversal when calculating hash. Some nodes
(Motion, Projection) store non-trivial
information, which allows to distinguish
different plans. We came across this by
collision between two different queries:
```
SELECT w.n FROM t JOIN w ON t.n = w.n
LIMIT 3

SELECT id, count(*) FROM t
GROUP BY id
HAVING id > 2
LIMIT 3
```
These plan happened to have subtrees that match
exactly except for output of projection, that
we didn't traverse.

- fix this by traversing subtree fully

- ValuesRow node have `data` and `output`
fields refer to the same stuff in query
`values (1)`. For except between global
and sharded table we applied special
transformation, in which we cloned
global subtree.
- Subtree cloner didn't respect DAG structure
of our plan: there maybe multiple references
to the same node. Instead it expected a tree.
Fix that

Dmitry Rodionov authored 8 months ago and Denis Smirnov committed 5 months ago

Previous version was using yaml-rust which is marked as unmaintained.
This gets reported by dependency scanner we use for certification.
Though worth noting that serde-yaml itself is now archived. There is a
promising replacement library but no need to hurry with that just yet.
But anyway, we don't need this library in the production build, only
for tests. So, moved it to development dependencies.

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

- Support like operator with signature:

expr1 LIKE expr2 [ESCAPE expr3]

which returns TRUE only if expr1 matches the
string specified by expr2 (pattern). '_' in
pattern matches any single character, '%'
matches any character 0 or more times. All
other characters match itself according to
case.

- Optional escape clause specifies character
to use for escaping '_' and '%'

- to_params uses subtree iterator to create
parameters for cached query. But our plan
is a DAG, not a tree. We have multiple nodes
referring to the same node, this leads to
situation when we traverse the same subquery
node multiple times. This in term leads to
wrong number of parameters produces by
to_params
- fix this by keeping track of already traversed
parameter nodes in to_params

feat: support additional SubQuery children for any relational operator, interpret SubQuery with single output as expression

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>