/** Checks for type compatibility of column and expr. Returns compatible (possibly cast) expr. */
private Expr checkTypeCompatibility(Column column, Expr expr) throws AnalysisException {
// Check for compatible type, and add casts to the selectListExprs if necessary.
// We don't allow casting to a lower precision type.
Type colType = column.getType();
Type exprType = expr.getType();
// Trivially compatible.
if (colType.equals(exprType)) return expr;
Type compatibleType = Type.getAssignmentCompatibleType(colType, exprType);
// Incompatible types.
if (!compatibleType.isValid()) {
throw new AnalysisException(
String.format(
"Target table '%s' is incompatible with SELECT / PARTITION expressions.\n"
+ "Expression '%s' (type: %s) is not compatible with column '%s' (type: %s)",
targetTableName_, expr.toSql(), exprType, column.getName(), colType));
}
// Loss of precision when inserting into the table.
if (!compatibleType.equals(colType) && !compatibleType.isNull()) {
throw new AnalysisException(
String.format(
"Possible loss of precision for target table '%s'.\n"
+ "Expression '%s' (type: %s) would need to be cast to %s"
+ " for column '%s'",
targetTableName_, expr.toSql(), exprType, colType, column.getName()));
}
// Add a cast to the selectListExpr to the higher type.
return expr.castTo(compatibleType);
}
/**
* Expand "*" for a particular tuple descriptor by appending refs for each column to
* selectListExprs.
*
* @param analyzer
* @param alias
* @param desc
* @throws AnalysisException
*/
private void expandStar(Analyzer analyzer, String alias, TupleDescriptor desc)
throws AnalysisException {
for (Column col : desc.getTable().getColumnsInHiveOrder()) {
resultExprs.add(new SlotRef(new TableName(null, alias), col.getName()));
colLabels.add(col.getName().toLowerCase());
}
}
/**
* Expand "*" for a particular tuple descriptor by appending analyzed slot refs for each column to
* selectListExprs.
*/
private void expandStar(Analyzer analyzer, TableName tblName, TupleDescriptor desc)
throws AnalysisException, AuthorizationException {
for (Column col : desc.getTable().getColumnsInHiveOrder()) {
SlotRef slotRef = new SlotRef(tblName, col.getName());
slotRef.analyze(analyzer);
resultExprs_.add(slotRef);
colLabels_.add(col.getName().toLowerCase());
}
}
/*
* Builds results for a DESCRIBE <table> command. This consists of the column
* definition for each column in the table.
*/
private static TDescribeTableResult describeTableMinimal(Table table) {
TDescribeTableResult descResult = new TDescribeTableResult();
descResult.results = Lists.newArrayList();
// Get description of all the table's columns (includes partition columns).
for (Column column : table.getColumnsInHiveOrder()) {
TColumnValue colNameCol = new TColumnValue();
colNameCol.setString_val(column.getName());
TColumnValue dataTypeCol = new TColumnValue();
dataTypeCol.setString_val(column.getType().toString().toLowerCase());
TColumnValue commentCol = new TColumnValue();
commentCol.setString_val(column.getComment() != null ? column.getComment() : "");
descResult.results.add(
new TResultRow(Lists.newArrayList(colNameCol, dataTypeCol, commentCol)));
}
return descResult;
}
/**
* Performs three final parts of the analysis: 1. Checks type compatibility between all
* expressions and their targets
*
* <p>2. Populates partitionKeyExprs with type-compatible expressions, in Hive partition-column
* order, for all partition columns
*
* <p>3. Populates resultExprs_ with type-compatible expressions, in Hive column order, for all
* expressions in the select-list. Unmentioned columns are assigned NULL literal expressions.
*
* <p>If necessary, adds casts to the expressions to make them compatible with the type of the
* corresponding column.
*
* @throws AnalysisException If an expression is not compatible with its target column
*/
private void prepareExpressions(
List<Column> selectExprTargetColumns,
List<Expr> selectListExprs,
Table tbl,
Analyzer analyzer)
throws AnalysisException {
// Temporary lists of partition key exprs and names in an arbitrary order.
List<Expr> tmpPartitionKeyExprs = new ArrayList<Expr>();
List<String> tmpPartitionKeyNames = new ArrayList<String>();
int numClusteringCols = (tbl instanceof HBaseTable) ? 0 : tbl.getNumClusteringCols();
// Check dynamic partition columns for type compatibility.
for (int i = 0; i < selectListExprs.size(); ++i) {
Column targetColumn = selectExprTargetColumns.get(i);
Expr compatibleExpr = checkTypeCompatibility(targetColumn, selectListExprs.get(i));
if (targetColumn.getPosition() < numClusteringCols) {
// This is a dynamic clustering column
tmpPartitionKeyExprs.add(compatibleExpr);
tmpPartitionKeyNames.add(targetColumn.getName());
}
selectListExprs.set(i, compatibleExpr);
}
// Check static partition columns, dynamic entries in partitionKeyValues will already
// be in selectExprTargetColumns and therefore are ignored in this loop
if (partitionKeyValues_ != null) {
for (PartitionKeyValue pkv : partitionKeyValues_) {
if (pkv.isStatic()) {
// tableColumns is guaranteed to exist after the earlier analysis checks
Column tableColumn = table_.getColumn(pkv.getColName());
Expr compatibleExpr = checkTypeCompatibility(tableColumn, pkv.getValue());
tmpPartitionKeyExprs.add(compatibleExpr);
tmpPartitionKeyNames.add(pkv.getColName());
}
}
}
// Reorder the partition key exprs and names to be consistent with the target table
// declaration. We need those exprs in the original order to create the corresponding
// Hdfs folder structure correctly.
for (Column c : table_.getColumns()) {
for (int j = 0; j < tmpPartitionKeyNames.size(); ++j) {
if (c.getName().equals(tmpPartitionKeyNames.get(j))) {
partitionKeyExprs_.add(tmpPartitionKeyExprs.get(j));
break;
}
}
}
Preconditions.checkState(partitionKeyExprs_.size() == numClusteringCols);
// Make sure we have stats for partitionKeyExprs
for (Expr expr : partitionKeyExprs_) {
expr.analyze(analyzer);
}
// Finally, 'undo' the permutation so that the selectListExprs are in Hive column
// order, and add NULL expressions to all missing columns.
for (Column tblColumn : table_.getColumnsInHiveOrder()) {
boolean matchFound = false;
for (int i = 0; i < selectListExprs.size(); ++i) {
if (selectExprTargetColumns.get(i).getName().equals(tblColumn.getName())) {
resultExprs_.add(selectListExprs.get(i));
matchFound = true;
break;
}
}
// If no match is found, either the column is a clustering column with a static
// value, or it was unmentioned and therefore should have a NULL select-list
// expression.
if (!matchFound) {
if (tblColumn.getPosition() >= numClusteringCols) {
// Unmentioned non-clustering columns get NULL literals with the appropriate
// target type because Parquet cannot handle NULL_TYPE (IMPALA-617).
resultExprs_.add(NullLiteral.create(tblColumn.getType()));
}
}
}
// TODO: Check that HBase row-key columns are not NULL? See IMPALA-406
if (needsGeneratedQueryStatement_) {
// Build a query statement that returns NULL for every column
List<SelectListItem> selectListItems = Lists.newArrayList();
for (Expr e : resultExprs_) {
selectListItems.add(new SelectListItem(e, null));
}
SelectList selectList = new SelectList(selectListItems);
queryStmt_ = new SelectStmt(selectList, null, null, null, null, null, null);
queryStmt_.analyze(analyzer);
}
}
/**
* Checks that the column permutation + select list + static partition exprs + dynamic partition
* exprs collectively cover exactly all columns in the target table (not more of fewer).
*/
private void checkColumnCoverage(
ArrayList<Column> selectExprTargetColumns,
Set<String> mentionedColumnNames,
int numSelectListExprs,
int numStaticPartitionExprs)
throws AnalysisException {
boolean isHBaseTable = (table_ instanceof HBaseTable);
int numClusteringCols = isHBaseTable ? 0 : table_.getNumClusteringCols();
// Check that all columns are mentioned by the permutation and partition clauses
if (selectExprTargetColumns.size() + numStaticPartitionExprs != table_.getColumns().size()) {
// We've already ruled out too many columns in the permutation and partition clauses
// by checking that there are no duplicates and that every column mentioned actually
// exists. So all columns aren't mentioned in the query. If the unmentioned columns
// include partition columns, this is an error.
List<String> missingColumnNames = Lists.newArrayList();
for (Column column : table_.getColumns()) {
if (!mentionedColumnNames.contains(column.getName())) {
// HBase tables have a single row-key column which is always in position 0. It
// must be mentioned, since it is invalid to set it to NULL (which would
// otherwise happen by default).
if (isHBaseTable && column.getPosition() == 0) {
throw new AnalysisException(
"Row-key column '"
+ column.getName()
+ "' must be explicitly mentioned in column permutation.");
}
if (column.getPosition() < numClusteringCols) {
missingColumnNames.add(column.getName());
}
}
}
if (!missingColumnNames.isEmpty()) {
throw new AnalysisException(
"Not enough partition columns mentioned in query. Missing columns are: "
+ Joiner.on(", ").join(missingColumnNames));
}
}
// Expect the selectListExpr to have entries for every target column
if (selectExprTargetColumns.size() != numSelectListExprs) {
String comparator = (selectExprTargetColumns.size() < numSelectListExprs) ? "fewer" : "more";
String partitionClause =
(partitionKeyValues_ == null) ? "returns" : "and PARTITION clause return";
// If there was no column permutation provided, the error is that the select-list
// has the wrong number of expressions compared to the number of columns in the
// table. If there was a column permutation, then the mismatch is between the
// select-list and the permutation itself.
if (columnPermutation_ == null) {
int totalColumnsMentioned = numSelectListExprs + numStaticPartitionExprs;
throw new AnalysisException(
String.format(
"Target table '%s' has %s columns (%s) than the SELECT / VALUES clause %s"
+ " (%s)",
table_.getFullName(),
comparator,
table_.getColumns().size(),
partitionClause,
totalColumnsMentioned));
} else {
String partitionPrefix =
(partitionKeyValues_ == null) ? "mentions" : "and PARTITION clause mention";
throw new AnalysisException(
String.format(
"Column permutation %s %s columns (%s) than "
+ "the SELECT / VALUES clause %s (%s)",
partitionPrefix,
comparator,
selectExprTargetColumns.size(),
partitionClause,
numSelectListExprs));
}
}
}
/**
* Sets table_ based on targetTableName_ and performs table-type specific analysis: - Partition
* clause is invalid for unpartitioned Hdfs tables and HBase tables - Overwrite is invalid for
* HBase tables - Check INSERT privileges as well as write access to Hdfs paths - Cannot insert
* into a view Adds table_ to the analyzer's descriptor table if analysis succeeds.
*/
private void setTargetTable(Analyzer analyzer) throws AnalysisException {
// If the table has not yet been set, load it from the Catalog. This allows for
// callers to set a table to analyze that may not actually be created in the Catalog.
// One example use case is CREATE TABLE AS SELECT which must run analysis on the
// INSERT before the table has actually been created.
if (table_ == null) {
if (!targetTableName_.isFullyQualified()) {
targetTableName_ = new TableName(analyzer.getDefaultDb(), targetTableName_.getTbl());
}
table_ = analyzer.getTable(targetTableName_, Privilege.INSERT);
} else {
targetTableName_ = new TableName(table_.getDb().getName(), table_.getName());
PrivilegeRequestBuilder pb = new PrivilegeRequestBuilder();
analyzer.registerPrivReq(
pb.onTable(table_.getDb().getName(), table_.getName())
.allOf(Privilege.INSERT)
.toRequest());
}
// We do not support inserting into views.
if (table_ instanceof View) {
throw new AnalysisException(
String.format("Impala does not support inserting into views: %s", table_.getFullName()));
}
boolean isHBaseTable = (table_ instanceof HBaseTable);
int numClusteringCols = isHBaseTable ? 0 : table_.getNumClusteringCols();
if (partitionKeyValues_ != null && numClusteringCols == 0) {
if (isHBaseTable) {
throw new AnalysisException(
"PARTITION clause is not valid for INSERT into "
+ "HBase tables. '"
+ targetTableName_
+ "' is an HBase table");
} else {
// Unpartitioned table, but INSERT has PARTITION clause
throw new AnalysisException(
"PARTITION clause is only valid for INSERT into "
+ "partitioned table. '"
+ targetTableName_
+ "' is not partitioned");
}
}
if (table_ instanceof HdfsTable) {
HdfsTable hdfsTable = (HdfsTable) table_;
if (!hdfsTable.hasWriteAccess()) {
throw new AnalysisException(
String.format(
"Unable to INSERT into target table "
+ "(%s) because Impala does not have WRITE access to at least one HDFS path"
+ ": %s",
targetTableName_, hdfsTable.getFirstLocationWithoutWriteAccess()));
}
for (int colIdx = 0; colIdx < numClusteringCols; ++colIdx) {
Column col = hdfsTable.getColumns().get(colIdx);
// Hive has a number of issues handling BOOLEAN partition columns (see HIVE-6590).
// Instead of working around the Hive bugs, INSERT is disabled for BOOLEAN
// partitions in Impala. Once the Hive JIRA is resolved, we can remove this
// analysis check.
if (col.getType() == Type.BOOLEAN) {
throw new AnalysisException(
String.format(
"INSERT into table with BOOLEAN " + "partition column (%s) is not supported: %s",
col.getName(), targetTableName_));
}
}
}
if (isHBaseTable && overwrite_) {
throw new AnalysisException("HBase doesn't have a way to perform INSERT OVERWRITE");
}
// Add target table to descriptor table.
analyzer.getDescTbl().addReferencedTable(table_);
}