The Cursor returned will be capable of scanning rows into a structure.
It replaces part of the function for why the Emitter existed. The
Emitter would both join the resulting rows and then transform the values
into a models.Row so it could be returned to the results.
In the future, we will be able to use the Cursor directly to write out
values which should be more memory efficient.
Along with modifying ExecutionContext to be a context and have the
TaskManager return the context itself, this also creates a Monitor
interface and exposes the Monitor through the Context. This way, we can
access the monitor from within the query.Select method and keep all of
the limits inside of the query package instead of leaking them into the
statement executor.
An eventual goal is to remove the InterruptCh from the IteratorOptions
and use the Context instead, but for now, we'll just assign the done
channel from the Context to the IteratorOptions so at least they refer
to the same channel.
Remove the `Query` prefix from some structs and interfaces. They were
there so when the query engine was in the same package as influxql,
these would be differentiated. Now that the package name is query, the
extra prefix seems redundant.
Since possibly v0.9 DELETE SERIES has had the unwanted side effect of
removing series from the index when the last traces of series data are
removed from TSM. This occurred because the inmem index was rebuilt on
startup, and if there was no TSM data for a series then there could be
not series to add to the index.
This commit returns to the original (documented) DROP/DETETE SERIES
behaviour. As such, when issuing DROP SERIES all instances of matching
series will be removed from both the TSM engine and the index. When
issuing DELETE SERIES only TSM data will be removed.
It is up to the operator to remove series from the index.
NB, this commit does not address how to remove series data from the
series file when a shard rolls over.
The previous sha was taken from a revision on a devel branch that I
thought would continue staying in the tree after it was merged. That
revision was rebased away and the API was changed for the logger.
This updates the usage of the logger and adds a simple package for
constructing the base logger.
The 1.0 version of zap changed the format of the default console logger
so this change moves over to this new logger instead of attempting to
retain backwards compatibility with the old format.
This commit adds time support to SHOW TAG VALUES. Time can be used as
both a lower and upper boundary. However, there are some caveats.
For the `inmem` index, filtering by time will still return all results
because the index data is shared across shards.
For the `tsi1` index, filtering by time will only work down to the shard
lever. Specifically, when querying by time all shards within that time
range will be used to generate the results.
When a meta query does not include a time component then it can be
answered exclusively by the index. This should result in a much faster
query execution that if the TSM engine was engaged.
This commit rewrites the following queries such that they make use
of the index where no time component is present:
- SHOW MEASUREMENTS
- SHOW SERIES
- SHOW TAG KEYS
- SHOW FIELD KEYS
* Introduces EXPLAIN ANALYZE command, which
produces a detailed tree of operations used to
execute the query.
introduce context.Context to APIs
metrics package
* create groups of named measurements
* safe for concurrent access
tracing package
EXPLAIN ANALYZE implementation for OSS
Serialize EXPLAIN ANALYZE traces from remote nodes
use context.Background for tests
group with other stdlib packages
additional documentation and remove unused API
use influxdb/pkg/testing/assert
remove testify reference
This allows the query:
SELECT mean(value) FROM cpu GROUP BY time(1d)
To function in some way that makes sense. The upper limit is implicitly
the `now()` starting time and the lower limit will be whichever interval
the lowest point falls into.
When no lower bound is specified and `max-select-buckets` is specified,
the query will only consider points that would satisfy
`max-select-buckets`. So if you have one point written in 1970, have
another point within the last minute, and then do the above query with
`max-select-buckets` being equal to 10, the older point from 1970 will
not be considered.
It prints the statistics of each iterator that will access the storage
engine. For each access of the storage engine, it will print the number
of shards that will potentially be accessed, the number of files that
may be accessed, the number of series that will be created, the number
of blocks, and the size of those blocks.
Now, the prepared statement keeps the open resource and closing the open
resource created from `Prepare` is the responsibility of the prepared
statement.
This also nils out the local shard mapping after it is closed to prevent
it from being used after it is closed.
The first call is to compile the query. This performs some initial
processing that can be done before having any access to the shards. At
the moment, it does very little, but it's intended to be changed to
eventually perform initial validations of the query and create an
internal graph structure for the execution of the query.
The second call is to prepare the query. This step has access to the
shard mapper. Right now, it just maps the shards and rewrites the fields
of the query for any wildcards. In the future, it is intended to do the
above, but also to prepare the final directed acyclical graph that will
execute the query.
The third call is to select the query. This step is intended to create
all of the iterators for processing the query. At the moment, much of
the work intended for the second step is performed in the third step.
The statement rewriting logic should be in the query engine as part of
preparing a query. This creates a shard mapper interface that the query
engine expects and then passes it to the query engine instead of
requiring the query to be preprocessed before being input into the query
engine. This interface is (mostly) the same as the old interface, just
moved to a different package.
The ConditionExpr function is more accurate because it parses the
condition and ensures that time conditions are actually used correctly.
That means that attempting to combine conditions with OR will not result
in the query silently pretending it's an AND and nested conditions work
correctly so there is only one way to read the query.
It also extracts the non-time conditions into a separate condition so we
can stop attempting to parse around the time conditions in lower layers
of the storage engine. This change does not remove those hacks, but a
following commit should be able to sanitize the condition and remove
them.
This change provides a clear separation between the query engine
mechanics and the query language so that the language can be parsed and
dealt with separate from the query engine itself.
Writing points outside of a retention policy range were silently dropped. They
are dropped to prevent creating a shard that will be immediately deleted. These
dropped points were silent and did not return an error respone to the caller.
Fixes#8392
The timezone for a query can now be added to the end with something like
`TZ("America/Los_Angeles")` and it will localize the results of the
query to be in that timezone. The offset will automatically be set to
the offset for that timezone and offsets will automatically adjust for
daylight savings time so grouping by a day will result in a 25 hour day
once a year and a 23 hour day another day of the year.
The automatic adjustment of intervals for timezone offsets changing will
only happen if the group by period is greater than the timezone offset
would be. That means grouping by an hour or less will not be affected by
daylight savings time, but a 2 hour or 1 day interval will be.
The default timezone is UTC and existing queries are unaffected by this
change.
When times are returned as strings (when `epoch=1` is not used), the
results will be returned using the requested timezone format in RFC3339
format.
Jacob Marble
Jonathan A. Sternberg
Edd Robinson
Andrew Hare
Jonathan A. Sternberg
Ben Johnson
Stuart Carnie
Andrew Hare
Joe LeGasse
Jason Wilder
Jason Wilder