The main purpose of this pr is to import `fileCache` for lakehouse reading remote files.
Use the local disk as the cache for reading remote file, so the next time this file is read,
the data can be obtained directly from the local disk.
In addition, this pr includes a few other minor changes
Import File Cache:
1. The imported `fileCache` is called `block_file_cache`, which uses lru replacement policy.
2. Implement a new FileRereader `CachedRemoteFilereader`, so that the logic of `file cache` is hidden under `CachedRemoteFilereader`.
Other changes:
1. Add a new interface `fs()` for `FileReader`.
2. `IOContext` adds some statistical information to count the situation of `FileCache`
Co-authored-by: Lightman <31928846+Lchangliang@users.noreply.github.com>
Fix three bugs when read iceberg v2 tables:
1. The `delete position` in `delete file` represents the position of delete row in the entire file, but the `read range` in
`RowGroupReader` represents the position in current row group. Therefore, we need to subtract the position of first
row of current row group from `delete position`.
2. When only reading the partition columns, `RowGroupReader` skips processing the `delete position`.
3. If the `delete position` has delete all rows in a row group, the `read range` is empty, but we read the whole row
group in such case.
Optimize four performance issues:
1. We change `delete position` to `delete range`, and then merge `delete range` and `read range` into the final read
ranges. This process is too tedious and time-consuming. . we can merge `delete position` and `read range` directly.
2. `delete position` is ordered in a `delete file`, so we can use merge-sort, instead of ordered-set.
3. Initialize `RowGroupReader` when reading, instead of initialize all row groups when opening a `ParquetReader`, to
save memory usage, and the same as `IcebergReader`.
4. Change the recursive call of `_do_lazy_read` to loop logic.
Fix three bugs:
1. DataTypeFactory::create_data_type is missing the conversion of binary type, and OrcReader will failed
2. ScalarType#createType is missing the conversion of binary type, and ExternalFileTableValuedFunction will failed
3. fmt::format can't generate right format string, and will be failed
The external table file path cache may out of date, which will cause orc reader to visit non-exist files.
In this case, orc file reader is nullptr.
This pr is to check the reader before using it to avoid core dump of visiting nullptr.
Read predicate columns firstly, and use VExprContext(push-down predicates)
to generate the select vector, which is then applied to read the non-predicate columns.
The data in non-predicate columns may be skipped by select vector, so the value-decode-time can be reduced.
If a whole page can be skipped, the decompress-time can also be reduced.
# Proposed changes
Implement predicate pushdown in `OrcReader` by converting doris `ColumnValueRange` to orc `SearchArgument`.
## Remaining problems
1. Orc support `not in`, which may have effect on bloom filter. However, doris `ScanNode` has not push down `not in` to file scanner.
2. Orc support `is null`, and row range has `hasNull` identifier. However, `_contain_null` in `ColumnValueRange` is ambiguous. `_contain_null = true` only means that the value can be nullable, not equal to null.
3. `DateTimeV2` has lost microsecond precision in `ColumnValueRange`, which may cause filtering error when a min-max value equals to the predicate value.
4. `DateTimeV1` is not accurate enough, and only saved to seconds.
5. Orc support the predicate pushdown of `float&double` type, but doris has not push down `float&double` type for precision reason.
