This PR is meant to get all columns from an index
based on the TrackExistence row.
`All()` is a PQL function that can be used as a typical
row object. Optional arguments are `limit` and `offset`.
This PR adds a field name (string) to the return types
which represent the values from a specific field. For example,
a TopN query on field `x` would be `TopN(x)` and have results
like:
```
[]Pair{
{ID: 14, Count: 10},
{ID: 3, Count: 8},
{ID: 7, Count: 3},
}
```
In order to know what field this result type refers to, we wrap
`[]Pair` in a new struct called `PairsField` which contains an
addition `Field` string where `x` is stored.
This is useful for informing the gRPC server how to construct
more appropriate headers for the result stream (in this case,
the column headers can now be "x" and "count").
Similar logic was applied to `RowIdentifiers` and `Pair` as well.
There is a TODO in the `StringWithSubj` method because the value
types really depend on the subject type (for example, `count` uses
uint64, while `sum` uses int64). I'm waiting to address this
until we decide how to handle sums of floats (Decimal), because
that will affect this logic as well.
This PR adds support for a `having` argument in a `GroupBy` query.
Usage looks like this:
```
GroupBy(Rows(a), having=Condition(count > 10))
GroupBy(Rows(a), aggregate=Sum(field=b), having=Condition(sum > 100))
```
In order to standardize results as streams of RowResponse,
this PR introduces two interfaces `StreamClient` and
`StreamServer`) which mirror the grpc stream interfaces.
Upstream users (sqlmapper, vdsm, etc) can implement
instances of these interfaces to ensure that results can
stream through the entire sytem in an expected way.
This PR also fixes a couple of missing data types.
This change allows one to query Pilosa fields and indexes directly
with integer row and column ids even when key translation is
enabled. This was previously disallowed during query
translation... I'm not sure why, but it can be quite useful for
debugging and testing to be able to use IDs directly. I have a test in
go-pilosa which uses this functionality.
I also simplified a bunch of the test code which was of the form:
```
else {
if blah {
}
}
```
to be:
```
else if blah {
```
which I think is pretty harmless.
I also changed a snapshot log line that has been bugging me to be
Debug level so that it isn't generating lots of useless logs for long
running Pilosa instances.
It turns out that we need to recompute the set of shards whenever
a query is cross-index. Otherwise we get partial results in unexpected
ways sometimes.
There's two actual changes here, but they're closely related.
First, handle named parameters for precalls, not just indexed parameters.
Second, when doing translation for a call, check whether it specifies an
index, and if it does, use that index instead of the current index for
the translation.
the threshold.
Prior to this commit, if a cache value was reduced to a value
that fell below the threshold, the operation would be ignored
and the cached value would remain at the old, higher value.
This commit also fixes logic which reduces a cached value within
the framework of uint64 values by subracting the absolute value
of the negative value (since adding a negitive doesn't work with
unsigned integers).
In this case, the test is reading from the translateStore
replica before the translateStore replication has had time to
deliver its log to the replica. The only way to truly address
this in the translate store would be to route all key misses
that happen on a read-only replica to the primary translate
store (or somehow know when the primary is done sending to
replicas) for actual verification that the key does not exist.
That's more involved than we want to do here; this PR just
addresses the problem in the test.
