Merge pull request #93 from Fedomn/fix-incorrect-test-result

fix(test): fix incorrect subquery slt result

Merge pull request #59 from Fedomn/release-v0.4

chore(release): release v0.4

Merge pull request #40 from Fedomn/release-v0.3

chore(release): release v0.3

Merge pull request #24 from Fedomn/hahs-agg

feat(hash_agg): introduce HashAggregation

Merge pull request #11 from Fedomn/executor

feat(executor): init executor and finish basic SQL query