Opt zstd block decompression by `ZSTD_decompressDCtx()` to replace streaming decompression.
It will improve performance but consume more memory.
Test result:
- env: 1 node(16 cores, 64G).
- parquet column: 100 million rows of char(255) column.
- result: 5.2 -> 4.6.
Fixed the problem of not being able to read parquet lz4 compressed format. By default, it is decompressed according to the Hadoop lz4 format. If it fails, it will fall back to the standard lz4 compression format.
After the outer catch exception, faststring resize reserve build may throw a memory alloc failure exception from the Allocator.
Currently page body compress will catch memory alloc failure exception
Currently, there are some useless includes in the codebase. We can use a tool named include-what-you-use to optimize these includes. By using a strict include-what-you-use policy, we can get lots of benefits from it.
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>
ZSTD compression is fast with high compression ratio. It can be used to archive higher compression ratio
than default Lz4f codec for storing cost sensitive data such as logs.
Compared to Lz4f codec, we see zstd codec get 35% compressed size off, 30% faster at first time read without OS page
cache, 40% slower at second time read with OS page cache in the following comparison test.
test data: 25GB text log, 110 million rows
test table: test_table(ts varchar(30), log string)
test SQL: set enable_vectorized_engine=1; select sum(length(log)) from test_table
be.conf: disable_storage_page_cache = true
set this config to disable doris page cache to avoid all data cached in memory for test real decompression speed.
test result
master branch with lz4f codec result:
- compressed size 4.3G
- SQL first exec time(read data from disk + decompress + little computation) : 18.3s
- SQL second exec time(read data from OS pagecache + decompress + little computation) : 2.4s
this branch with zstd codec (hardcode enable it) result:
- compressed size: 2.8G
- SQL first exec time: 12.8s
- SQL second exec time: 3.4s
