Qingqing Zhou
Qingqing Zhou
1. parameter query ```select * from a where i > ?``` depending on ?'s actual value, we may have indexed or sequential scan. Say we want to cache the plan...
We have some type coerce code in place but needs strengthen it. Tasks: 1. add more test cases covering type coerce; - operators like +/-/like - functions like year/Aggs -...
1. not all operators are implemented 2. research an inter-op implementation framework to support half codegen and half interpreted plan (Expr already support it) 3. ~~Row copy avoidance: a major...
sometimes they are consistent but sometimes they are not (FromQuery)
pure cascades wont' work and needs some approximate join resolver https://dl.gi.de/bitstream/handle/20.500.12116/21735/B2-1.pdf?sequence=1&isAllowed=y
The theory is here: https://arxiv.org/abs/1711.08330 and an implementation with PostgreSQL is here: https://github.com/postgrespro/aqo A related topic is re-optimization (https://arxiv.org/pdf/1902.08291.pdf), where when executor detects discrepancy between optimizer's estimation and actual data,...
~~1. introduce sequence plan~~ 2. non-inline plan: (1) don't double count cost: 3 ctes refs equals to 1 cte cost 3. inline plan (mixed with non-inline plan) (1) inline plan...
// disable it for now due to introduce table alias (a__1) confusing matching // sql = "select a2 from a where a1 in (select a2 from a where exists (select...
1. we shall reduce unittest time by parallize the many unittest - currently they are not using all cores. Be careful, tpcds/h are not parallizable because they both have 'customer'...