CreateQuery t17 (children 3) Identifier t17 Columns definition (children 1) ExpressionList (children 2) ColumnDeclaration a (children 1) DataType UInt32 ColumnDeclaration b (children 1) DataType UInt32 Storage definition (children 4) Function MergeTree Function less (children 1) ExpressionList (children 2) Identifier a Literal UInt64_90 Identifier a Set