Query Plans

Seaquel renders query execution plans as interactive diagrams, making it straightforward to find bottlenecks and understand how the database executes your SQL.

Running a plan

1. Write your query in the editor.
2. Click EXPLAIN in the toolbar to see the estimated plan, or EXPLAIN ANALYZE to execute the query and get actual metrics.
3. The plan renders as an interactive tree powered by SvelteFlow.

Reading the plan tree

Each node in the tree represents an operation the database performs. Metrics shown per node include:

• Estimated vs. actual cost — compare what the planner predicted against reality
• Row estimates vs. actual rows — spot cardinality misestimates
• Execution time — how long each operation took (EXPLAIN ANALYZE only)
• Index usage — which indexes were used, if any
• Filter and hash conditions — conditions applied at each step
• Loop counts — how many times a nested loop executed

Planning time and total execution time are displayed at the top of the plan for quick reference.

Hot path analysis

Seaquel automatically detects bottlenecks and highlights them with severity indicators:

• Green — performing well
• Yellow — moderate cost, worth reviewing
• Red — significant bottleneck, likely needs optimization

This lets you jump straight to the most expensive operations without reading the entire plan.

Database support

Query plans are supported for:

• PostgreSQL — EXPLAIN and EXPLAIN ANALYZE
• MySQL — EXPLAIN and EXPLAIN ANALYZE

Tips for optimization

• Compare estimated vs. actual rows — large gaps often indicate missing or stale statistics.
• Look for sequential scans on large tables where an index scan would be faster.
• Check loop counts on nested loops — high counts multiply the cost of inner operations.
• Run EXPLAIN ANALYZE to get real timing data, not just estimates.