BuildPattern builds a Pattern from Operand, EngineType and child Patterns.

GetOperand maps logical plan operator to Operand.

NewPattern creates a pattern node according to the Operand and EngineType.

EngineAll is the EngineTypeSet for all of the EngineTypes.

EngineTiDB stands for groups which is above `Gather`s and will be executed in TiDB layer.

EngineTiDBOnly is the EngineTypeSet for EngineTiDB only.

EngineTiFlash stands for groups which is below `Gather`s and will be executed in TiFlash layer.

EngineTiFlashOnly is the EngineTypeSet for EngineTiFlash only.

EngineTiKV stands for groups which is below `Gather`s and will be executed in TiKV layer.

EngineTiKVOnly is the EngineTypeSet for EngineTiKV only.

EngineTiKVOrTiFlash is the EngineTypeSet for (EngineTiKV | EngineTiFlash).

OperandAggregation is the operand for LogicalAggregation.

OperandAny is a placeholder for any Operand.

OperandApply is the operand for LogicalApply.

OperandDataSource is the operand for DataSource.

OperandIndexScan is the operand for IndexScan.

OperandJoin is the operand for LogicalJoin.

OperandLimit is the operand for LogicalLimit.

OperandLock is the operand for LogicalLock.

OperandMaxOneRow is the operand for LogicalMaxOneRow.

OperandMemTableScan is the operand for MemTableScan.

OperandProjection is the operand for LogicalProjection.

OperandSelection is the operand for LogicalSelection.

OperandShow is the operand for Show.

OperandSort is the operand for LogicalSort.

OperandTableDual is the operand for LogicalTableDual.

OperandTableScan is the operand for TableScan.

OperandTiKVSingleGather is the operand for TiKVSingleGather.

OperandTopN is the operand for LogicalTopN.

OperandUnionAll is the operand for LogicalUnionAll.

OperandUnionScan is the operand for LogicalUnionScan.

OperandUnsupported is the operand for unsupported operators.

OperandWindow is the operand for window function.

Pattern defines the match pattern for a rule.

EngineType is determined by whether it's above or below `Gather`s.

EngineTypeSet is the bit set of EngineTypes.

Operand is the node of a pattern tree, it represents a logical expression operator.