Add fillBlockCache option to bypass RocksDB block cache #14234

3.8/aql/invocation-with-arangosh.md

@@ -169,8 +169,17 @@ There are further options that can be passed in the *options* attribute of the *
   the query result cache is disabled, and that they will be automatically inserted into
   the query result cache when it is active in non-demand mode.
 
+- *fillBlockCache*: if set to *true* or not specified, this will make the query store
+  the data it reads via the RocksDB storage engine in the RocksDB block cache. This is
+  usually the desired behavior. The option can be set to *false* for queries that are
+  known to either read a lot of data that would thrash the block cache, or for queries
+  that read data known to be outside of the hot set. By setting the option
+  to *false*, data read by the query will not make it into the RocksDB block cache if
+  it is not already in there, thus leaving more room for the actual hot set.
+
 - *profile*: if set to *true* or *1*, returns extra timing information for the query. The timing
-  information is accessible via the *getExtra* method of the query result. Set to *2* the query will include execution stats per query plan node in sub-attribute *stats.nodes* of the *extra* return attribute.
+  information is accessible via the *getExtra* method of the query result. Set to *2* the query will
+  include execution stats per query plan node in sub-attribute *stats.nodes* of the *extra* return attribute.
   Additionally the query plan is returned in the sub-attribute *extra.plan*.
 
 - *maxWarningCount*: limits the number of warnings that are returned by the query if

3.8/release-notes-api-changes38.md

@@ -324,9 +324,16 @@ in ArangoDB 3.8:
   only be picked up for indexes of type "persistent", "hash" and "skiplist" (where the
   latter two are aliases for "persistent" nowadays).
 
-The REST endpoint at GET `/_api/collection/<collection>/checksum` now also works
-in cluster setups. In previous versions, this endpoint was not supported in cluster
-setups and returned HTTP 501 (Not implemented).
+- The REST endpoint at GET `/_api/collection/<collection>/checksum` now also works
+  in cluster setups. In previous versions, this endpoint was not supported in cluster
+  setups and returned HTTP 501 (Not implemented).
+
+- The HTTP REST API endpoint `POST /_api/cursor` can now handle an 
+  additional sub-attribute `fillBlockCache` for its `options` attribute.
+  `fillBlockCache` controls whether the to-be-executed query should
+  populate the RocksDB block cache with the data read by the query.
+  This is an optional attribute, and its default value is `true`, meaning
+  that the block cache will be populated (introduced in v3.8.1).
 
 ### Endpoints deprecated
 

3.9/aql/invocation-with-arangosh.md

@@ -169,8 +169,17 @@ There are further options that can be passed in the *options* attribute of the *
   the query result cache is disabled, and that they will be automatically inserted into
   the query result cache when it is active in non-demand mode.
 
+- *fillBlockCache*: if set to *true* or not specified, this will make the query store
+  the data it reads via the RocksDB storage engine in the RocksDB block cache. This is
+  usually the desired behavior. The option can be set to *false* for queries that are
+  known to either read a lot of data that would thrash the block cache, or for queries
+  that read data known to be outside of the hot set. By setting the option
+  to *false*, data read by the query will not make it into the RocksDB block cache if
+  it is not already in there, thus leaving more room for the actual hot set.
+
 - *profile*: if set to *true* or *1*, returns extra timing information for the query. The timing
-  information is accessible via the *getExtra* method of the query result. Set to *2* the query will include execution stats per query plan node in sub-attribute *stats.nodes* of the *extra* return attribute.
+  information is accessible via the *getExtra* method of the query result. Set to *2* the query will
+  include execution stats per query plan node in sub-attribute *stats.nodes* of the *extra* return attribute.
   Additionally the query plan is returned in the sub-attribute *extra.plan*.
 
 - *maxWarningCount*: limits the number of warnings that are returned by the query if

3.9/release-notes-api-changes39.md

@@ -19,6 +19,14 @@ integrations for ArangoDB 3.9.
 
 ### Endpoints augmented
 
+The HTTP REST API endpoint `POST /_api/cursor` can now handle an 
+additional sub-attribute `fillBlockCache` for its `options` attribute.
+`fillBlockCache` controls whether the to-be-executed query should
+populate the RocksDB block cache with the data read by the query.
+This is an optional attribute, and its default value is `true`, meaning
+that the block cache will be populated. This functionality was also backported
+to v3.8.1.
+
 ### Endpoints moved
 
 ### Endpoints removed