DBA compare, TTL, and advisor workflows

Operators coming from other DBA tools often look for schema compare, change plans, and TTL inventory. This page is the map of what ships today. All of it is recommend-only. Open any of these from the sidebar or ⌘K (title, route, or aliases such as ddl, schema diff, config diff, ttl inventory).

What exists today

Settings compare (/settings-diff)

Open Tools → Settings Diff. Compare saved hosts (env, per-user, and browser connections), or pick two cluster nodes when the current host has 2+ replicas. Filter to rows that differ, or to settings changed from default. Search, column filters, sort, resize, reorder, and density live on the comparison table. One saved host compares against setting defaults; use Add host to diff another node. Two or more hosts keep an all-hosts matrix with an optional pair picker. The page is gated by the settings feature id — see Settings.

Nothing on this page writes to ClickHouse. To change a setting, use SET, ALTER TABLE … MODIFY SETTING, or edit the server config yourself.

Schema compare (/schema-diff)

Open Tools → Schema Compare. Pick a source and target host (or two nodes of the current cluster) from the compact pair picker. With one saved host the page explains it needs two connections (staging vs prod) and offers Add host. Tables are grouped by database (collapse them into folders). Selecting a table pretty-prints side-by-side CREATE TABLE with line numbers and diff highlights, plus a copyable recommend-only plan. Copy recommended SQL lives on the source/target toolbar (all safe statements, or only tables you check). Each table's plan card can copy that table only. It never applies DDL.

Advisor (/advisor)

Open Tools → Advisor. Two tabs:

• Query Advisor — paste a SELECT that reads a table, pick a slow query (loads it and runs analysis), or look up a query_id from system.query_log. Table-less SQL such as SELECT 1 is explained as "needs a table", not treated as a failed analysis.
• Schema & Settings — scan a database or table for column lint, TTL / partition health, engine / Distributed pairing, and settings findings.

The same recommend-only engine is available from the AI agent and the MCP server. There is no Apply button.

Storage economics (/storage-economics)

Open System → Storage Economics. Three tables:

• Compression by table (from system.parts)
• Storage policies
• TTL storage moves (parts that already moved because of TTL)

The inventory of every table's TTL expression and partition health lives on Tables → TTL & Partitions (/ttl-partition-health). The same rules surface as the TTL & Partition Health card on /health (count of flagged tables; click for the breakdown). This page stays move history and current economics.

Health: TTL & Partition Health (/health)

Open Health. The TTL & Partition Health card counts MergeTree tables that need review: 500+ partitions (warning) / 1000+ (critical copy on the inventory page), a time-based PARTITION BY with no table TTL, or 10+ active parts per partition. Click the card for the flagged-table breakdown, then open TTL & Partitions for the full inventory. Recommend-only — there is no Apply button and nothing here runs ALTER TTL or DROP PARTITION.

Explorer single-host DDL (/explorer)

The Data Explorer shows CREATE TABLE for the table on the current host. Table Overview also runs the same recommend-only schema lint as Advisor. Cross-host or node-vs-node DDL compare lives on /schema-diff.

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