There should be 2 kinds of ScanNode:
OlapScanNode
ExternalScanNode
The Backends used for ExternalScanNode should be controlled by FederationBackendPolicy.
But currently, only FileScanNode is controlled by FederationBackendPolicy, other scan node such as MysqlScanNode,
JdbcScanNode will use Mix Backend even if we enable and prefer to use Compute Backend.
In this PR, I modified the hierarchy of ExternalScanNode, the new hierarchy is:
ScanNode
OlapScanNode
SchemaScanNode
ExternalScanNode
MetadataScanNode
DataGenScanNode
EsScanNode
OdbcScanNode
MysqlScanNode
JdbcScanNode
FileScanNode
FileLoadScanNode
FileQueryScanNode
MaxComputeScanNode
IcebergScanNode
TVFScanNode
HiveScanNode
HudiScanNode
And previously, the BackendPolicy is the member of FileScanNode, now I moved it to the ExternalScanNode.
So that all subtype ExternalScanNode can use BackendPolicy to choose Compute Backend to execute the query.
All all ExternalScanNode should implement the abstract method createScanRangeLocations().
For scan node like jdbc scan node/mysql scan node, the scan range locations will be selected randomly from
compute node(if preferred).
And for compute node selection. If all scan nodes are external scan nodes, and prefer_compute_node_for_external_table
is set to true, the BE for this query will only select compute nodes.
Function esquery does not work because there is a problem parsing the first parameter type.
The first parameter, which is SlotRef, will be cast to CastExpr. This will cause error while generating ES DSL.
Add more types to adapt esquery function.
In previous implementation, when doing list partition prune, we need to generation `rangeToId`
every time we doing prune.
But `rangeToId` is actually a static data that should be create-once-use-every-where.
So for hive partition, I created the `rangeToId` and all other necessary data structures for partition prunning
in partition cache, so that we can use it directly.
In my test, the cost of partition prune for 10000 partitions reduce from 8s -> 0.2s.
Aslo add "partition" info in explain string for hive table.
```
| 0:VEXTERNAL_FILE_SCAN_NODE |
| predicates: `nation` = '0024c95b' |
| inputSplitNum=1, totalFileSize=4750, scanRanges=1 |
| partition=1/10000 |
| numNodes=1 |
| limit: 10 |
```
Bug fix:
1. Fix bug that es scan node can not filter data
2. Fix bug that query es with predicate like `where substring(test2,2) = "ext2";` will fail at planner phase.
`Unexpected exception: org.apache.doris.analysis.FunctionCallExpr cannot be cast to org.apache.doris.analysis.SlotRef`
TODO:
1. Some problem when quering es version 8: ` Unexpected exception: Index: 0, Size: 0`, will be fixed later.
