* Implements the grammar of the batch delete #4051
* Process create, alter table when table has delete sign column
* Support the syntax for enabling the delete column
* Automatically filtered deleted data in the select statement.
* Automatically add delete sign when create rollup table
TODO:
* Optimize the reading and compaction logic on the be side, so that the data marked as deleted will be completely deleted during base compaction
1、Add a PushBrokerReader in push_handle.cpp.
2、PushBrokerReader wraps the ParquetScanner to support reading data from parquet format file through broker.
the num segments should be read from rowset meta pb.
But the previous code error caused this value not to be set in some cases.
So when init the rowset meta and find that the num_segments is 0(not set),
we will try to calculate the num segments from AlphaRowsetExtraMetaPB,
and then set the num_segments field.
This should only happen in some rowsets converted from old version.
and for all newly created rowsets, the num_segments field must be set.
Add dict encoding page for binary/string type data.
Construct a dict for original data, and save encoded id instead of
origin data to save space. If the dict is too big, then will automatically fall
back to plain encoding.
NOTE: This patch would modify all Backend's data.
And this will cause a very long time to restart be.
So if you want to interferer your product environment,
you should upgrade backend one by one.
1. Refactoring be is to clarify the structure the codes.
2. Use unique id to indicate a rowset.
Nameing rowset with tablet_id and version will lead to
many conflicts among compaction, clone, restore.
3. Extract an rowset interface to encapsulate rowsets
with different format.
* Add streaming load feature. You can execute 'help stream load;' to see more information.
Changed:
* Loading phase of a certain table can be parallelized, to reduce the load job execution time when multi load jobs to a single table.
* Using RocksDB to save the header info of tablets in Backends, to reduce the IO operations and increate speeding of restarting.
Fixed:
* A lot of bugs fixed.
