System Views

KalamDB exposes computed system.* views for metadata and runtime observability. This page focuses on the new session and transaction views added for explicit transaction support.

system.sessions

system.sessions shows active PostgreSQL gRPC bridge sessions tracked by the server.

It is intentionally pg-session-focused:

• pg_kalam sessions appear here while they are active.
• Native /v1/api/sql requests do not create rows here.
• The CLI \sessions command runs this view directly.

Common query

SELECT *
FROM system.sessions
ORDER BY last_seen_at DESC, session_id;

Active-transaction query

SELECT session_id, transaction_id, transaction_state, transaction_has_writes
FROM system.sessions
WHERE transaction_id IS NOT NULL
ORDER BY last_seen_at DESC, session_id;

Columns

system.transactions

system.transactions shows active explicit transactions across all server origins.

Use it to observe transaction state regardless of whether the transaction came from pg_kalam or native KalamDB SQL.

• Common origin values include PgRpc for the PostgreSQL extension and SqlBatch for native /v1/api/sql execution.
• Rows disappear immediately after COMMIT, ROLLBACK, timeout cleanup, or request-end cleanup.

Common query

SELECT transaction_id, owner_id, origin, state, write_count
FROM system.transactions
ORDER BY origin, transaction_id;

Capacity-oriented query

SELECT transaction_id, origin, state, age_ms, idle_ms, write_bytes, touched_tables_count
FROM system.transactions
ORDER BY age_ms DESC;

Columns

Key Distinction

• system.sessions shows live PostgreSQL bridge sessions only.
• system.transactions shows active explicit transactions across all supported origins.
• A native /v1/api/sql transaction appears in system.transactions, but not in system.sessions.

Related

• Data Manipulation
• CLI Guide
• PostgreSQL Extension SQL Syntax