@Override
public int execute(DriverContext driverContext) {
PrintStream out = null;
try {
Path resFile = new Path(work.getResFile());
OutputStream outS = resFile.getFileSystem(conf).create(resFile);
out = new PrintStream(outS);
QB qb = work.getQb();
TokenRewriteStream stream = work.getCtx().getTokenRewriteStream();
String program = "sq rewrite";
ASTNode ast = work.getAst();
try {
addRewrites(stream, qb, program, out);
out.println(
"\nRewritten Query:\n"
+ stream.toString(program, ast.getTokenStartIndex(), ast.getTokenStopIndex()));
} finally {
stream.deleteProgram(program);
}
out.close();
out = null;
return (0);
} catch (Exception e) {
console.printError(
"Failed with exception " + e.getMessage(), "\n" + StringUtils.stringifyException(e));
return (1);
} finally {
IOUtils.closeStream(out);
}
}
void addRewrites(
TokenRewriteStream stream,
QBSubQuery sq,
String program,
PrintStream out,
String qbAlias,
boolean isWhere,
StringBuilder addedJoins) {
ASTNode sqNode = sq.getOriginalSubQueryASTForRewrite();
ASTNode tokQry = getQueryASTNode(sqNode);
ASTNode tokInsert = (ASTNode) tokQry.getChild(1);
ASTNode tokWhere = null;
for (int i = 0; i < tokInsert.getChildCount(); i++) {
if (tokInsert.getChild(i).getType() == HiveParser.TOK_WHERE) {
tokWhere = (ASTNode) tokInsert.getChild(i);
break;
}
}
SubQueryDiagnostic.QBSubQueryRewrite diag = sq.getDiagnostic();
String sqStr = diag.getRewrittenQuery();
String joinCond = diag.getJoiningCondition();
/*
* the SubQuery predicate has been hoisted as a Join. The SubQuery predicate is replaced
* by a 'true' predicate in the Outer QB's where/having clause.
*/
stream.replace(program, sqNode.getTokenStartIndex(), sqNode.getTokenStopIndex(), "1 = 1");
String sqJoin = " " + getJoinKeyWord(sq) + " " + sqStr + " " + joinCond;
addedJoins.append(" ").append(sqJoin);
String postJoinCond = diag.getOuterQueryPostJoinCond();
if (postJoinCond != null) {
stream.insertAfter(program, tokWhere.getTokenStopIndex(), " and " + postJoinCond);
}
String qualifier = isWhere ? "Where Clause " : "Having Clause ";
if (qbAlias != null) {
qualifier = qualifier + "for Query Block '" + qbAlias + "' ";
}
out.println(String.format("\n%s Rewritten SubQuery:\n%s", qualifier, diag.getRewrittenQuery()));
out.println(
String.format(
"\n%s SubQuery Joining Condition:\n%s", qualifier, diag.getJoiningCondition()));
}