locks can get relinquished when Read() sees io.EOF
leading to prematurely closing of the readers
concurrent writes on the same object can have
undesired consequences here when these locks
are relinquished.
This change fixes handling of these types of queries:
- Double quoted column names with special characters:
SELECT "column.name" FROM s3object
- Double quoted column names with reserved keywords:
SELECT "CAST" FROM s3object
- Table name as prefix for column names:
SELECT S3Object."CAST" FROM s3object
I have built a fuzz test and it crashes heavily in seconds and will OOM shortly after.
It seems like supporting Parquet is basically a completely open way to crash the
server if you can upload a file and run s3 select on it.
Until Parquet is more hardened it is DISABLED by default since hostile
crafted input can easily crash the server.
If you are in a controlled environment where it is safe to assume no hostile
content can be uploaded to your cluster you can safely enable Parquet.
To enable Parquet set the environment variable `MINIO_API_SELECT_PARQUET=on`
while starting the MinIO server.
Furthermore, we guard parquet by recover functions.
String x might contain trimming spaces. And it needs to be trimmed. For
example, in csv files, there might be trimming spaces in a field that
ought to meet a query condition that contains the value without
trimming spaces. This applies to both intCast and floatCast functions.
enable linter using golangci-lint across
codebase to run a bunch of linters together,
we shall enable new linters as we fix more
things the codebase.
This PR fixes the first stage of this
cleanup.
This commit modifies csv parser, a fork of golang csv
parser to support a custom quote escape character.
The quote escape character is used to escape the quote
character when a csv field contains a quote character
as part of data.
The JSON stream library has no safe way of aborting while
Since we cannot expect the called to safely handle "Read" and "Close" calls we must handle this.
Also any Read error returned from upstream will crash the server. We preserve the errors and instead always return io.EOF upstream, but send the error on Close.
`readahead v1.3.1` handles Read after Close better.
Updates to `progressReader` is mostly to ensure safety.
Fixes#8481
Force sum/average to be calculated as a float.
As noted in #8221
> run SELECT AVG(CAST (Score as int)) FROM S3Object on
```
Name,Score
alice,80
bob,81
```
> AWS S3 gives 80.5 and MinIO gives 80.
This also makes overflows much more unlikely.
Updates #7475
The Java implementation has a 128KB buffer and a message must be emitted before that is used. #7475 therefore limits the message size to 128KB. But up to 256 bytes are written to the buffer in each call. This means we must emit a message before shorter than 128KB.
Therefore we change the limit to 128KB minus 256 bytes.
Queue output items and reuse them.
Remove the unneeded type system in sql and just use the Go type system.
In best case this is more than an order of magnitude speedup:
```
BenchmarkSelectAll_1M-12 1 1841049400 ns/op 274299728 B/op 4198522 allocs/op
BenchmarkSelectAll_1M-12 14 84833400 ns/op 169228346 B/op 3146541 allocs/op
```
