# Proposed changes
In the nereids. Before this PR: when we access some unexists tables. It will report the exception as follows:
```
mysql> select * from tt;
ERROR 1105 (HY000): errCode = 2, detailMessage = Unexpected exception: null
```
After this PR, it will get the following results:
```
mysql> select * from tt;
ERROR 1105 (HY000): errCode = 2, detailMessage = Unexpected exception: Table [tt] does not exist in database [default_cluster:test].
```
## Problem summary
It is because in this [function](f5af07f7b2/fe/fe-core/src/main/java/org/apache/doris/nereids/CascadesContext.java (L328)), we ignore the exception. So the size of `tables` in `CascadesContext` is zero not null. So we can only get null after `table = cascadesContext.getTableByName(tableName);`.
1. Remove an exec node method corresponding to a span and replace it with an exec node corresponding to a span;
2. Fix some problems with tracing in pipeline.
There are two problems of mini dump:
1、minidump do not load connect context to ThreadInfo, so it can not be get easily
2、minidump write maps with not concurrent protection, so the map size with change when we iterating map iterator
Solution:
1、loading connect context to minidump threading
2、use immutable map copy a new map before we actually doing iteration
ixu ubsan errors:
doris/be/src/util/string_parser.hpp:275:58: runtime error: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
doris/be/src/vec/functions/functions_comparison.h:214:51: runtime error: addition of unsigned offset to 0x7fea6c6b7010 overflowed to 0x7fea6c6b700c
doris/be/src/vec/functions/multiply.cpp:67:50: runtime error: signed integer overflow: 1295699415680000000 * 0x0000000000015401d0a4cd4890a77700 cannot be represented in type '__int128
doris/be/src/vec/aggregate_functions/aggregate_function_percentile_approx.h:445:73: runtime error: addition of unsigned offset to 0x7feca3343d10 overflowed to 0x7feca3343d08
doris/be/src/exec/schema_scanner/schema_tables_scanner.cpp:330:24: run
Usage: ./build-thirdparty.sh [options...] [packages...]
Optional options:
-j <num> build thirdparty parallel
--clean clean the extracted data
--continue <package> continue to build the remaining packages (starts from the specified package)
Examples:
1. Specify packages to build.
Build gflags, gtest and glog by executing ./build-thirdparty.sh gflags gtest glog.
2. Continue to build the remaining packages.
Build the remaining packages (starts from sse2neon) by executing ./build-thirdparty.sh --continue sse2neon.
We can support this by add a new properties for tvf, like :
`select * from hdfs("uri" = "xxx", ..., "compress_type" = "lz4", ...)`
User can:
Specify compression explicitly by setting `"compression" = "xxx"`.
Doris can infer the compression type by the suffix of file name(e.g. `file1.gz`)
Currently, we only support reading compress file in `csv` format, and on BE side, we already support.
All need to do is to analyze the `"compress_type"` on FE side and pass it to BE.
