> On Dec. 16, 2013, 10:01 p.m., Jacques Nadeau wrote: > > exec/java-exec/src/main/codegen/templates/CastFunctionsSrcVarLen.java, line > > 48 > > <https://reviews.apache.org/r/15871/diff/4/?file=398256#file398256line48> > > > > Can you take a quick look at what this looks like in machine code after > > optimized. I'm concerned that it will be inefficient.
The original code seems inefficient in that it first converts byte array into char array, then construct a string then parse into int/long etc. The fix is to decode the byte array directly into int/long, in a similar way how java's Integer/Long parse char array. This would improve performance, when the cast is applied many times in record batches. - Jinfeng ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/15871/#review30518 ----------------------------------------------------------- On Dec. 16, 2013, 9:52 a.m., Jinfeng Ni wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/15871/ > ----------------------------------------------------------- > > (Updated Dec. 16, 2013, 9:52 a.m.) > > > Review request for drill. > > > Repository: drill-git > > > Description > ------- > > The explicit cast function is treated as a special function call. Its syntax > in logical/physical plan: > > cast (input_expr as int | bigint | float4 | float8 | varchar(length) | > varbinary(length) ) > > The main code changes : > 1) parser change to read expression in logical/physical plan, which may > contain an explicit cast function > 2) FunctionRegistry.java is added with two methods to build a logical > expression for cast function. > 3) Add 3 function template to generate the different type of cast functions : > > CastFunctionsSrcVarLen.java : when source type has varied length, target > type has fixed length. > CastFunctionsTargetVarLen.java: when source type has fixed length, target > type has varied length. > CastFunctionsSrcVarLenTargetVarLen.java: when both source and target type > have varied length. > > Currently, the following 6 types can be cast into each other > float4, float8, int, bigint, varchar, varbinary. > > > Diffs > ----- > > > common/src/main/antlr3/org/apache/drill/common/expression/parser/ExprLexer.g > 76da965 > > common/src/main/antlr3/org/apache/drill/common/expression/parser/ExprParser.g > 7fc1651 > common/src/main/java/org/apache/drill/common/expression/FunctionCall.java > a8b7e01 > > common/src/main/java/org/apache/drill/common/expression/FunctionDefinition.java > fb00dc7 > > common/src/main/java/org/apache/drill/common/expression/FunctionRegistry.java > 73e1925 > > common/src/main/java/org/apache/drill/common/expression/OutputTypeDeterminer.java > 2f583d5 > > common/src/main/java/org/apache/drill/common/expression/fn/CastFunctionDefs.java > PRE-CREATION > exec/java-exec/src/main/codegen/data/Casts.tdd 760b0f9 > exec/java-exec/src/main/codegen/templates/CastFunctions.java 85a00b0 > exec/java-exec/src/main/codegen/templates/CastFunctionsSrcVarLen.java > PRE-CREATION > > exec/java-exec/src/main/codegen/templates/CastFunctionsSrcVarLenTargetVarLen.java > PRE-CREATION > exec/java-exec/src/main/codegen/templates/CastFunctionsTargetVarLen.java > PRE-CREATION > > exec/java-exec/src/main/java/org/apache/drill/exec/expr/fn/DrillFuncHolder.java > e001ffe > > exec/java-exec/src/main/java/org/apache/drill/exec/expr/fn/FunctionImplementationRegistry.java > 5bbab76 > > exec/java-exec/src/main/java/org/apache/drill/exec/vector/ValueHolderHelper.java > 077c693 > exec/java-exec/src/main/java/org/apache/drill/exec/work/FragmentRunner.java > d003972 > > exec/java-exec/src/test/java/org/apache/drill/exec/physical/impl/TestCastFunctions.java > PRE-CREATION > exec/java-exec/src/test/resources/functions/cast/testCastBigInt.json > PRE-CREATION > exec/java-exec/src/test/resources/functions/cast/testCastFloat4.json > PRE-CREATION > exec/java-exec/src/test/resources/functions/cast/testCastFloat8.json > PRE-CREATION > exec/java-exec/src/test/resources/functions/cast/testCastInt.json > PRE-CREATION > exec/java-exec/src/test/resources/functions/cast/testCastNested.json > PRE-CREATION > exec/java-exec/src/test/resources/functions/cast/testCastVarBinary.json > PRE-CREATION > exec/java-exec/src/test/resources/functions/cast/testCastVarChar.json > PRE-CREATION > > Diff: https://reviews.apache.org/r/15871/diff/ > > > Testing > ------- > > 7 physical plans are used in junit testcase testCastFunctions.java > > 1) testCastInt.json : when target type is int, and src type is bigint, > float4, float8, varchar, varbinary. > 2) testCastBigInt.json: when target type is bigint, and src type is int, > float4, float8, varchar, varbinary. > 3) testCastFloat4.json: when target type is float4, and src type is int, > bigint, float8, varchar, varbinary. > 4) testCastFloat8.json: when target type is float8, and src type is int, > bigint, float4, varchar, varbinary > 5) testCastVarChar.json: when target tyep is varchar, and src type is int, > bigint, float4,float8, varbinary > 6) testCastVarBinary.json: when target type is varbinary, and src type is > int, bigint, float4, float8, varchar. > 7) testCastNested.json: test cast functions is nested in another cast > function, or another normal functions. > > > > Thanks, > > Jinfeng Ni > >
