docs: document live view TTL, retention and Parquet conversion

documentation/changelog.mdx

@@ -17,12 +17,17 @@ This page tracks significant updates to the QuestDB documentation.
 ### New
 
 - [Migrate QuestDB onto the Kubernetes Operator](/docs/enterprise-kubernetes-operator/getting-started/migrate/) - Move an existing Enterprise deployment onto the Operator with a replica-first cutover: restore the source backup, consume replication WAL, then promote after a controlled source drain
+- [ALTER LIVE VIEW](/docs/query/sql/alter-live-view/) - New reference page for managing a live view's disk tier: `SET TTL`, `DROP PARTITION`, `CONVERT PARTITION` between native and Parquet, `RESUME WAL` and `SUSPEND WAL`, with the asynchronous apply, why a manual `DROP PARTITION` can be undone by recovery, the rejected clauses, the per-clause permissions, and how replicas apply the statements locally
 
 ### Updated
 
 - [Kafka connector](/docs/connect/message-brokers/kafka/) - Updated for QWP with a quick start, guidance on preventing duplicates and recovering from outages, and migration steps for existing HTTP pipelines
 - [Kubernetes Operator](/docs/enterprise-kubernetes-operator/) - Refreshed for Operator 0.2.1 across installation, configuration, high availability, backup and restore, known limitations, troubleshooting, and the generated [API reference](/docs/enterprise-kubernetes-operator/reference/api/)
 - [Rust](/docs/connect/clients/rust/) and [C and C++](/docs/connect/clients/c-and-cpp/) clients - Documented the UUID byte order, which was previously unstated. `Buffer::column_uuid` takes `(lo, hi)` where `hi` is the most significant half, matching `java.util.UUID`, and the chunk setter takes the 16 bytes in canonical RFC-4122 order
+- [CREATE LIVE VIEW](/docs/query/sql/create-live-view/#ttl) - Documented the `TTL` clause, its partition-size granularity rule, and how the window is enforced during the initial seed
+- [Live views](/docs/concepts/live-views/#retention-and-storage-format) - New retention and storage format section, replacing the "no TTL on the view" limitation, plus the replication behavior of the durable-tier statements
+- [TTL](/docs/concepts/ttl/#on-live-views) - Live views take TTL at creation and afterwards, evaluated when the view's own table commits
+- [Parquet](/docs/concepts/parquet/#bloom-filters-for-in-place-conversion) - Corrected the in-place conversion example: `ALTER TABLE ... CONVERT PARTITION` names the option `fpp` and requires a quoted value, while `bloom_filter_fpp` is the `COPY ... TO` spelling
 
 ## August 2026
 

documentation/concepts/live-views.md

@@ -262,6 +262,37 @@ supported. A keep-last `UPSERT` replacement at an earlier timestamp is reflected
 in the view. A view over a deduplicated base is one `FLUSH EVERY` cycle behind
 rather than sub-cycle fresh, because its refresh is coupled to base apply.
 
+## Retention and storage format
+
+A live view's disk tier is a WAL-backed table, and
+[`ALTER LIVE VIEW`](/docs/query/sql/alter-live-view/) manages it with the same
+verbs a table has:
+
+- [`SET TTL`](/docs/query/sql/alter-live-view/#set-ttl), or the `TTL` clause of
+  [`CREATE LIVE VIEW`](/docs/query/sql/create-live-view/#ttl), drops partitions
+  older than a retention window. The view enforces it on its own commits, so the
+  window holds without operator action.
+- [`DROP PARTITION`](/docs/query/sql/alter-live-view/#drop-partition) removes
+  partitions on demand.
+- [`CONVERT PARTITION`](/docs/query/sql/alter-live-view/#convert-partition)
+  moves partitions between the native and Parquet storage formats.
+
+A view's retention is independent of its base table's. The view stores computed
+rows, so a wide projection can outgrow the base table even when both keep the
+same window.
+
+A live view is derived rather than ingested, which gives its retention two
+properties a table's does not have. The
+[`ALTER LIVE VIEW`](/docs/query/sql/alter-live-view/) page covers both in detail:
+
+- **A manual `DROP PARTITION` is not permanent.** An out-of-order base commit, or
+  a rebuild from the view's `START FROM` boundary, recomputes output over the
+  dropped period and writes those rows back. TTL survives recovery, because the
+  rule is re-applied to the recomputed rows.
+- **The two tiers evict independently.** Rows removed from disk can still be
+  served from the in-memory tier until it is rebuilt, so neither statement makes
+  data unreadable at a known point in time.
+
 ## Monitoring
 
 The [`live_views()`](/docs/query/functions/meta/#live_views) function exposes
@@ -343,14 +374,16 @@ in [Base table lifecycle](#base-table-lifecycle).
 - **Deterministic queries only.** Non-deterministic functions such as `now()`,
   `sysdate()`, `systimestamp()`, and `rnd_*()` are rejected in the projection,
   the `WHERE` filter, and window-function arguments.
-- **No TTL on the view.** Live-view disk growth is unbounded in this version.
-  Size retention on the base table instead.
+- **Retention is partition-granular.** A live view drops whole partitions, as a
+  table does. Choose the view's `PARTITION BY` with the retention window in
+  mind, and see [Retention and storage format](#retention-and-storage-format).
 
 ## Tradeoffs
 
 - **Storage grows with output.** The computed rows are stored on the live view's
   disk tier in addition to the base table's rows. For wide projections or long
-  retention the view's footprint can exceed the base table.
+  retention the view's footprint can exceed the base table. Bound it with a
+  [TTL](#retention-and-storage-format) on the view.
 - **No admission control.** A view that cannot keep up with ingestion stays
   correct but stale, with no automatic throttle or drop.
 - **Per-partition state for partitioned windows grows with distinct partition
@@ -391,6 +424,14 @@ A role switch continues the local refresh state; it does not reconstruct or
 transfer the former primary's live-view rows. Replica freshness therefore also
 depends on base-table replication and apply lag.
 
+[`ALTER LIVE VIEW`](/docs/query/sql/alter-live-view/) statements that manage the
+disk tier do replicate. They travel over a replicated control table and each node
+applies them to its own copy of the view, holding a partition change until its own
+refresh has reached the base-table progress the primary had when the change was
+taken. A
+node with live views or refresh disabled applies them through the ordinary WAL
+apply job.
+
 ### Backup and restore
 
 A live view is captured by the object-store backup like a materialized view: its
@@ -402,6 +443,8 @@ base table.
 
 - **SQL commands**
   - [`CREATE LIVE VIEW`](/docs/query/sql/create-live-view/): Create a live view
+  - [`ALTER LIVE VIEW`](/docs/query/sql/alter-live-view/): Manage a live view's
+    retention, storage format and WAL
   - [`DROP LIVE VIEW`](/docs/query/sql/drop-live-view/): Remove a live view
 
 - **Related concepts**

documentation/concepts/parquet.md

@@ -131,14 +131,15 @@ optionally set the false positive probability (FPP) using `WITH`:
 ```questdb-sql title="Convert with explicit bloom filter columns"
 ALTER TABLE trades CONVERT PARTITION TO PARQUET
 WHERE timestamp < '2025-08-31'
-WITH (bloom_filter_columns = 'symbol,side', bloom_filter_fpp = 0.01);
+WITH (bloom_filter_columns = 'symbol,side', fpp = '0.01');
 ```
 
 :::note
 
 When an explicit `bloom_filter_columns` list is provided, it overrides any
 per-column `PARQUET(BLOOM_FILTER)` metadata on the table. If the option is
-omitted, per-column metadata is used.
+omitted, per-column metadata is used. The option is named `fpp` here, and its
+value must be quoted. `COPY ... TO` spells the same setting `bloom_filter_fpp`.
 
 :::
 

documentation/concepts/ttl.md

@@ -90,6 +90,33 @@ A view's TTL is independent of its base table's TTL. For full syntax, see
 and
 [ALTER MATERIALIZED VIEW SET TTL](/docs/query/sql/alter-mat-view-set-ttl/).
 
+### On live views
+
+[Live views](/docs/concepts/live-views/) take TTL the same way, bounding the
+disk tier that holds their computed rows:
+
+```questdb-sql
+-- At view creation
+CREATE LIVE VIEW trades_ma
+FLUSH EVERY 1s
+PARTITION BY DAY
+TTL 4 WEEKS
+START FROM NOW
+AS
+SELECT timestamp, symbol,
+  avg(price) OVER (PARTITION BY symbol ORDER BY timestamp ROWS 300 PRECEDING)
+    AS moving_avg
+FROM trades;
+
+-- On an existing view
+ALTER LIVE VIEW trades_ma SET TTL 4 WEEKS;
+```
+
+A live view evaluates its TTL when its own table commits, which happens on the
+`FLUSH EVERY` cadence while the view is producing rows. For full syntax, see
+[CREATE LIVE VIEW](/docs/query/sql/create-live-view/#ttl) and
+[ALTER LIVE VIEW SET TTL](/docs/query/sql/alter-live-view/#set-ttl).
+
 ## How TTL works
 
 TTL drops partitions based on the **partition's time range**, not individual row