storage: add cluster setting delete_compaction_excise.enabled

This change adds a cluster setting to be able to dynamically
disable excises in delete-only compactions. Excises allow
for range deletions / range key deletions to be applied to
sstables even if they don't fully overlap with the sstable;
we just produce virtual sstables for the remainder of the sstable.

Epic: none

Release note: None

docs/generated/settings/settings-for-tenants.txt

@@ -386,6 +386,7 @@ sql.txn.read_committed_isolation.enabled	boolean	true	set to true to allow trans
 sql.txn.repeatable_read_isolation.enabled (alias: sql.txn.snapshot_isolation.enabled)	boolean	false	set to true to allow transactions to use the REPEATABLE READ isolation level if specified by BEGIN/SET commands	application
 sql.txn_fingerprint_id_cache.capacity	integer	100	the maximum number of txn fingerprint IDs stored	application
 storage.columnar_blocks.enabled	boolean	false	set to true to enable columnar-blocks to store KVs in a columnar format	system-visible
+storage.delete_compaction_excise.enabled	boolean	true	set to false to direct Pebble to not partially excise sstables in delete-only compactions	system-visible
 storage.ingestion.value_blocks.enabled	boolean	true	set to true to enable writing of value blocks in ingestion sstables	application
 storage.max_sync_duration	duration	20s	maximum duration for disk operations; any operations that take longer than this setting trigger a warning log entry or process crash	system-visible
 storage.max_sync_duration.fatal.enabled	boolean	true	if true, fatal the process when a disk operation exceeds storage.max_sync_duration	application

docs/generated/settings/settings.html

@@ -340,6 +340,7 @@
 <tr><td><div id="setting-sql-txn-snapshot-isolation-enabled" class="anchored"><code>sql.txn.repeatable_read_isolation.enabled<br />(alias: sql.txn.snapshot_isolation.enabled)</code></div></td><td>boolean</td><td><code>false</code></td><td>set to true to allow transactions to use the REPEATABLE READ isolation level if specified by BEGIN/SET commands</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-sql-txn-fingerprint-id-cache-capacity" class="anchored"><code>sql.txn_fingerprint_id_cache.capacity</code></div></td><td>integer</td><td><code>100</code></td><td>the maximum number of txn fingerprint IDs stored</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-storage-columnar-blocks-enabled" class="anchored"><code>storage.columnar_blocks.enabled</code></div></td><td>boolean</td><td><code>false</code></td><td>set to true to enable columnar-blocks to store KVs in a columnar format</td><td>Dedicated/Self-hosted (read-write); Serverless (read-only)</td></tr>
+<tr><td><div id="setting-storage-delete-compaction-excise-enabled" class="anchored"><code>storage.delete_compaction_excise.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>set to false to direct Pebble to not partially excise sstables in delete-only compactions</td><td>Dedicated/Self-hosted (read-write); Serverless (read-only)</td></tr>
 <tr><td><div id="setting-storage-experimental-eventually-file-only-snapshots-enabled" class="anchored"><code>storage.experimental.eventually_file_only_snapshots.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>set to false to disable eventually-file-only-snapshots (kv.snapshot_receiver.excise.enabled must also be false)</td><td>Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-storage-ingest-split-enabled" class="anchored"><code>storage.ingest_split.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>set to false to disable ingest-time splitting that lowers write-amplification</td><td>Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-storage-ingestion-value-blocks-enabled" class="anchored"><code>storage.ingestion.value_blocks.enabled</code></div></td><td>boolean</td><td><code>true</code></td><td>set to true to enable writing of value blocks in ingestion sstables</td><td>Serverless/Dedicated/Self-Hosted</td></tr>

pkg/storage/pebble.go

@@ -111,6 +111,18 @@ var columnarBlocksEnabled = settings.RegisterBoolSetting(
 	settings.WithPublic,
 )
 
+// deleteCompactionsCanExcise controls whether delete compactions can
+// apply rangedels/rangekeydels on sstables they partially apply to, through
+// an excise operation, instead of just applying the rangedels/rangekeydels
+// that fully delete sstables.
+var deleteCompactionsCanExcise = settings.RegisterBoolSetting(
+	settings.SystemVisible,
+	"storage.delete_compaction_excise.enabled",
+	"set to false to direct Pebble to not partially excise sstables in delete-only compactions",
+	metamorphic.ConstantWithTestBool(
+		"storage.delete_compaction_excise.enabled", true), /* defaultValue */
+	settings.WithPublic)
+
 // IngestAsFlushable controls whether ingested sstables that overlap the
 // memtable may be lazily ingested: written to the WAL and enqueued in the list
 // of flushables (eg, memtables, large batches and now lazily-ingested
@@ -1228,6 +1240,9 @@ func newPebble(ctx context.Context, cfg engineConfig) (p *Pebble, err error) {
 	cfg.opts.Experimental.EnableColumnarBlocks = func() bool {
 		return columnarBlocksEnabled.Get(&cfg.settings.SV)
 	}
+	cfg.opts.Experimental.EnableDeleteOnlyCompactionExcises = func() bool {
+		return deleteCompactionsCanExcise.Get(&cfg.settings.SV)
+	}
 
 	auxDir := cfg.opts.FS.PathJoin(cfg.env.Dir, base.AuxiliaryDir)
 	if !cfg.env.IsReadOnly() {