Query Optimizer

Ctrl+Enter

Steps

Pseudocode

Statistics & indexes

Change a table’s size or click a column to add / drop its index. The query is re-planned at once, the rewrite stays the same, because rules never use statistics.

StorageCost of one random page read

Legend

▦Table
σSelection (filter)
πProjection
×Cross product
⋈Join
⋉Semi join
γGroup / aggregate
↓Sort · # Limit
Derived condition
Being changed

Ctrl+Enter	Optimize the query
Space	Play / pause
→ ←	Next / previous step
Home End	First / last step
1–4	Jump to a stage
E	Edit the query
Q	Show the whole query / one line
X	Next example
?	This help