Add `JSON` datatype, following features are implemented by this PR:
1. `CREATE` tables with `JSON` type columns
2. `INSERT` values containing `JSON` type value stored in `String`, which is represented as binary format(AKA `JSONB`) at BE
3. `SELECT` JSON columns
Detail design refers [DSIP-016: Support JSON type](https://cwiki.apache.org/confluence/display/DORIS/DSIP-016%3A+Support+JSON+type)
* add JSONB data storage format type
* fix JsonLiteral resolve bug
* add DataTypeJson case in data_type_factory
* add JSON syntax check in FE
* add operators for jsonb_document, currently not support comparison between any JSON type value
* add ColumnJson and DataTypeJson
* add JsonField to store JsonValue
* add JsonValue to convert String JSON to BINARY JSON and JsonLiteral case for vliteral
* add push_json for MysqlResultWriter
* JSON column need no zone_map_index
* Revert "JSON column need no zone_map_index"
This reverts commit f71d1ce1ded9dbae44a5d58abcec338816b70d79.
* add JSON writer and reader, ignore zone-map for JSON column
* add json_to_string for DataTypeJson
* add olap_data_convertor for JSON type
* add some enum
* add OLAP_FIELD_TYPE_JSON type, FieldTypeTraits for it and corresponding cases or functions
* fix column_json offsets overflow bug, format code
* remove useless TODOs, add CmpType cases for JSON type
* add license header
* format license
* format be codes
* resolve rebase master conflicts
* fix bugs for CREATE and meta related code
* refactor JsonValue constructors, add fe JSON cases and fix some bugs, reformat codes
* modification be codes along code review advice
* fix rebase conflicts with master
* add unit test for json_value and column_json
* fix rebase error
* rename json to jsonb
* fix some data convert bugs, set Mysql type to JSON
Fix bugs:
1. Fe need to send file format (e.g. parquet, orc ...) to be while processing load jobs using new scanner.
2. Try to get parquet file column type from SchemaElement.type before getting from Logical type and Converted type.
1. HttpServer threads allocate bytebuffer and put them into streamload pipe, but scanner thread release them with query tracker.
2. We can assume brpc allocate memory in doris thread.
Above problems leads to wrong result of memtracker.
The like predicate process data in block perform better than in row. Currently, only not null column is optimized, nullable column will be handled later.
SELECT COUNT(*) FROM hits WHERE URL LIKE '%google%';
before: ~680ms
after: ~570ms
Get schema from parquet reader.
The new VFileScanner need to get file schema (column name to type map) from parquet file while processing load job,
this pr is to set the type information for parquet columns.
refactor some arguments for parquet reader
1. Add new parquet context to wrap reader arguments
2. Reduced some arguments for function call
Co-authored-by: jinzhe <jinzhe@selectdb.com>
The new scanner (VFileScanner) need a counter to record two values in load job.
1. The number of rows unselected by pre-filter, and
2. The number of rows filtered by unmatched schema or other error. This pr is to implement the counter.
The mem hook consumes the orphan tracker by default. If the thread does not attach other trackers, by default all consumption will be passed to the process tracker through the orphan tracker.
In real time, consumption of all other trackers + orphan tracker consumption = process tracker consumption.
Ideally, all threads are expected to attach to the specified tracker, so that "all memory has its own ownership", and the consumption of the orphan mem tracker is close to 0, but greater than 0.
Following the iteration order of the hash table will result in out-of-order access to aggregate states, which is very inefficient.
Traversing aggregate states in memory write order can significantly improve memory read efficiency.
Test
hash table items count: 3.35M
Before this optimization: insert keys into column takes 500ms
With this optimization only takes 80ms
Refactor of scanners. Support broker load.
This pr is part of the refactor scanner tasks. It provide support for borker load using new VFileScanner.
Work still in progress.
# Proposed changes
[Parquet v1.11+ supports page skipping](https://github.com/apache/parquet-format/blob/master/PageIndex.md),
which helps the scanner reduce the amount of data scanned, decompressed, decoded, and insertion.
According to the performance FlameGraph, decompression takes up 20% cpu time.
If a page can be filtered as a whole, the page can not be decompressed.
However, the row numbers between pages are not aligned. Columns containing predicates can be filtered by page granularity,
but other columns need to be skipped within pages, so non predicate columns can only save the decoding and insertion time.
Array column needs the repetition level to align with other columns, so the array column can only save the decoding and insertion time.
## Explore
`OffsetIndex` in the column metadata can locate the page position.
Theoretically, a page can be completely skipped, including the time of reading from HDFS.
However, the average size of a page is around 500KB. Skipping a page requires calling the `skip`.
The performance of `skip` is low when it is called frequently,
and may not be better than continuous reading of large blocks of data (such as 4MB).
If multiple consecutive pages are filtered, `skip` reading can be performed according to`OffsetIndex`.
However, for the convenience of programming and readability, the data of all pages are loaded and filtered in turn.
Add some utils and provide the candidate row range (generated with skipped row range of each column)
to read for page index filter
this version support binary operator filter
todo:
- use context instead of structures in close()
- process complex type filter
- use this instead of row group minmax filter
- refactor _eval_binary() for row group filter and page index filter
Refactor the scanners for hms external catalog, work in progress.
Use VFileScanner, will remove NewFileParquetScanner, NewFileOrcScanner and NewFileTextScanner after fully tested.
Query for parquet file has been tested, still need to add readers for orc file, text file and load logic as well.
Fix _delete_sign_idx and _seq_col_idx when append_column or build_schema when load.
Tablet schema cache support recycle when schema sptr use count equals 1.
Add a http interface for flink-connector to sync ddl.
Improve tablet->tablet_schema() by max_version_schema.
Reuse compression ctx and buffer.
Use a global instance for every compression algorithm, and use a
thread saft buffer pool to reuse compression buffer, pool size is equal
to max parallel thread num in compression, and this will not be too large.
Test shows this feature increase 5% of data import and compaction.
Co-authored-by: yixiutt <yixiu@selectdb.com>
