void addRewrites(TokenRewriteStream stream, QB qb, String program, PrintStream out) {
QBSubQuery sqW = qb.getWhereClauseSubQueryPredicate();
QBSubQuery sqH = qb.getHavingClauseSubQueryPredicate();
if (sqW != null || sqH != null) {
ASTNode sqNode =
sqW != null
? sqW.getOriginalSubQueryASTForRewrite()
: sqH.getOriginalSubQueryASTForRewrite();
ASTNode tokQry = getQueryASTNode(sqNode);
ASTNode tokFrom = (ASTNode) tokQry.getChild(0);
StringBuilder addedJoins = new StringBuilder();
if (sqW != null) {
addRewrites(stream, sqW, program, out, qb.getId(), true, addedJoins);
}
if (sqH != null) {
addRewrites(stream, sqH, program, out, qb.getId(), false, addedJoins);
}
stream.insertAfter(program, tokFrom.getTokenStopIndex(), addedJoins);
}
Set<String> sqAliases = qb.getSubqAliases();
for (String sqAlias : sqAliases) {
addRewrites(stream, qb.getSubqForAlias(sqAlias).getQB(), program, 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()));
}
private String getJoinKeyWord(QBSubQuery sq) {
switch (sq.getJoinType()) {
case LEFTOUTER:
return "left outer join";
case LEFTSEMI:
return "left semi join";
case RIGHTOUTER:
return "right outer join";
case FULLOUTER:
return "full outer join";
case INNER:
default:
return "inner join";
}
}