Translate the measurement and field tag key names to their non-storage
names and add the `_start` and `_stop` tag keys to the output since
they aren't real tags, but ones that are added by range.
The RPC call should translate `_measurement` and `_field` to their
proper shortened byte strings when requesting the tag values.
This also fixes the planner rewrites to return the root node even when
no rewrite happened as this is required by the planner.
The TagValues API will perform a linear scan if there is no predicate;
otherwise, it will use the index to find a list of candidate series
keys.
TagKeys expects the predicate to be transformed such that
`_measurement` and `_field` are remapped to `\x00` and `\xff`
respectively.
There is one TODO marked to analyze the predicate for a
`\x00 = '<measurement>'` pattern. If found, the predicate can be
eliminated and fall back to a linear prefix scan by combining the org,
bucket and measurement. This is tracked by issue #13497.
If a pattern is seen that matches the `v1.tagValues(...)` call, then it
will be replaced with a direct RPC call to read the tag values for the
selected tag key which should be better optimized than reading from the
storage engine tsm1 files.
If a pattern is seen that matches reading the tag keys, it will be
replaced with a direct RPC call to read the tag keys which should be
better optimized than reading from the storage engine tsm1 files.
* Extend storage service protobuf with TagKeys and TagValues
Co-authored-by: Michael Desa <mjdesa@gmail.com>
Co-authored-by: Jacob Marble <jacobmarble@influxdata.com>
* Extend the reads.Store interface with new TagKeys and TagValues APIs
* Extend readservice.store to implement refactored reads.Store interface
* Implement a StringIterator gRPC writer / serializer
* Implement a StringIterator gRPC reader / deserializer
* Implement a StringIterator merger
Storage converts references to _value in filter predicates to $.
It then considers any predicate that does not reference $ to be
a tag predicate. Tag predicates are used to construct series index
cursors.
This commit fixes a bug where field comparisons were being included
in tag predicates due to the HasFieldValueKey function searching
for comparison expressions referencing _value instead of $. Because
all references to _value had already been replaced. An expression
of the form '$ < 3000' would be considered a tag expression and
therefore would be mistakenly included as a tag predicate.
Fixes#13159.
A cursor can be in process (local) or remote. Remote cursors have
already applied the `hasPoints` check, to reduce network traffic.
Testing whether the cursor has points again here:
https://github.com/influxdata/influxdb/blob/master/storage/reads/reader.go#L221
will always return `false` for a remote cursor that has applied the
NoPoints optimization.
This temporary fix allows the `hasPoints` function to differentiate
a streamCursor and always return true in that case.
jlapacik
Stuart Carnie
Jacob Marble
Jonathan A. Sternberg
Kelvin Wang
Ben Johnson
kelwang
Jacob Marble
Todd Persen
zhulongcheng
Jeff Wendling
Jeff Wendling
Lorenzo Affetti
Christopher M. Wolff
Edd Robinson