public MutationPlan compile(UpsertStatement upsert) throws SQLException {
final PhoenixConnection connection = statement.getConnection();
ConnectionQueryServices services = connection.getQueryServices();
final int maxSize =
services
.getProps()
.getInt(
QueryServices.MAX_MUTATION_SIZE_ATTRIB,
QueryServicesOptions.DEFAULT_MAX_MUTATION_SIZE);
final ColumnResolver resolver = FromCompiler.getResolverForMutation(upsert, connection);
final TableRef tableRef = resolver.getTables().get(0);
final PTable table = tableRef.getTable();
if (table.getType() == PTableType.VIEW) {
if (table.getViewType().isReadOnly()) {
throw new ReadOnlyTableException(
table.getSchemaName().getString(), table.getTableName().getString());
}
}
boolean isSalted = table.getBucketNum() != null;
final boolean isTenantSpecific = table.isMultiTenant() && connection.getTenantId() != null;
final boolean isSharedViewIndex = table.getViewIndexId() != null;
String tenantId = isTenantSpecific ? connection.getTenantId().getString() : null;
int posOffset = isSalted ? 1 : 0;
// Setup array of column indexes parallel to values that are going to be set
List<ColumnName> columnNodes = upsert.getColumns();
final List<PColumn> allColumns = table.getColumns();
Set<PColumn> addViewColumnsToBe = Collections.emptySet();
Set<PColumn> overlapViewColumnsToBe = Collections.emptySet();
int[] columnIndexesToBe;
int nColumnsToSet = 0;
int[] pkSlotIndexesToBe;
List<PColumn> targetColumns;
if (table.getViewType() == ViewType.UPDATABLE) {
addViewColumnsToBe = Sets.newLinkedHashSetWithExpectedSize(allColumns.size());
for (PColumn column : allColumns) {
if (column.getViewConstant() != null) {
addViewColumnsToBe.add(column);
}
}
}
ImmutableBytesWritable ptr = new ImmutableBytesWritable();
// Allow full row upsert if no columns or only dynamic ones are specified and values count match
if (columnNodes.isEmpty()
|| columnNodes.size() == upsert.getTable().getDynamicColumns().size()) {
nColumnsToSet = allColumns.size() - posOffset;
columnIndexesToBe = new int[nColumnsToSet];
pkSlotIndexesToBe = new int[columnIndexesToBe.length];
targetColumns = Lists.newArrayListWithExpectedSize(columnIndexesToBe.length);
targetColumns.addAll(Collections.<PColumn>nCopies(columnIndexesToBe.length, null));
int minPKPos = 0;
if (isTenantSpecific) {
PColumn tenantColumn = table.getPKColumns().get(minPKPos);
columnIndexesToBe[minPKPos] = tenantColumn.getPosition();
targetColumns.set(minPKPos, tenantColumn);
minPKPos++;
}
if (isSharedViewIndex) {
PColumn indexIdColumn = table.getPKColumns().get(minPKPos);
columnIndexesToBe[minPKPos] = indexIdColumn.getPosition();
targetColumns.set(minPKPos, indexIdColumn);
minPKPos++;
}
for (int i = posOffset, j = 0; i < allColumns.size(); i++) {
PColumn column = allColumns.get(i);
if (SchemaUtil.isPKColumn(column)) {
pkSlotIndexesToBe[i - posOffset] = j + posOffset;
if (j++ < minPKPos) { // Skip, as it's already been set above
continue;
}
minPKPos = 0;
}
columnIndexesToBe[i - posOffset + minPKPos] = i;
targetColumns.set(i - posOffset + minPKPos, column);
}
if (!addViewColumnsToBe.isEmpty()) {
// All view columns overlap in this case
overlapViewColumnsToBe = addViewColumnsToBe;
addViewColumnsToBe = Collections.emptySet();
}
} else {
// Size for worse case
int numColsInUpsert = columnNodes.size();
nColumnsToSet =
numColsInUpsert
+ addViewColumnsToBe.size()
+ (isTenantSpecific ? 1 : 0)
+ +(isSharedViewIndex ? 1 : 0);
columnIndexesToBe = new int[nColumnsToSet];
pkSlotIndexesToBe = new int[columnIndexesToBe.length];
targetColumns = Lists.newArrayListWithExpectedSize(columnIndexesToBe.length);
targetColumns.addAll(Collections.<PColumn>nCopies(columnIndexesToBe.length, null));
Arrays.fill(
columnIndexesToBe,
-1); // TODO: necessary? So we'll get an AIOB exception if it's not replaced
Arrays.fill(
pkSlotIndexesToBe,
-1); // TODO: necessary? So we'll get an AIOB exception if it's not replaced
BitSet pkColumnsSet = new BitSet(table.getPKColumns().size());
int i = 0;
// Add tenant column directly, as we don't want to resolve it as this will fail
if (isTenantSpecific) {
PColumn tenantColumn = table.getPKColumns().get(i + posOffset);
columnIndexesToBe[i] = tenantColumn.getPosition();
pkColumnsSet.set(pkSlotIndexesToBe[i] = i + posOffset);
targetColumns.set(i, tenantColumn);
i++;
}
if (isSharedViewIndex) {
PColumn indexIdColumn = table.getPKColumns().get(i + posOffset);
columnIndexesToBe[i] = indexIdColumn.getPosition();
pkColumnsSet.set(pkSlotIndexesToBe[i] = i + posOffset);
targetColumns.set(i, indexIdColumn);
i++;
}
for (ColumnName colName : columnNodes) {
ColumnRef ref =
resolver.resolveColumn(null, colName.getFamilyName(), colName.getColumnName());
PColumn column = ref.getColumn();
if (IndexUtil.getViewConstantValue(column, ptr)) {
if (overlapViewColumnsToBe.isEmpty()) {
overlapViewColumnsToBe = Sets.newHashSetWithExpectedSize(addViewColumnsToBe.size());
}
nColumnsToSet--;
overlapViewColumnsToBe.add(column);
addViewColumnsToBe.remove(column);
}
columnIndexesToBe[i] = ref.getColumnPosition();
targetColumns.set(i, column);
if (SchemaUtil.isPKColumn(column)) {
pkColumnsSet.set(pkSlotIndexesToBe[i] = ref.getPKSlotPosition());
}
i++;
}
for (PColumn column : addViewColumnsToBe) {
columnIndexesToBe[i] = column.getPosition();
targetColumns.set(i, column);
if (SchemaUtil.isPKColumn(column)) {
pkColumnsSet.set(pkSlotIndexesToBe[i] = SchemaUtil.getPKPosition(table, column));
}
i++;
}
for (i = posOffset; i < table.getPKColumns().size(); i++) {
PColumn pkCol = table.getPKColumns().get(i);
if (!pkColumnsSet.get(i)) {
if (!pkCol.isNullable()) {
throw new ConstraintViolationException(
table.getName().getString()
+ "."
+ pkCol.getName().getString()
+ " may not be null");
}
}
}
}
List<ParseNode> valueNodes = upsert.getValues();
QueryPlan plan = null;
RowProjector rowProjectorToBe = null;
final int nValuesToSet;
boolean sameTable = false;
boolean runOnServer = false;
UpsertingParallelIteratorFactory upsertParallelIteratorFactoryToBe = null;
final boolean isAutoCommit = connection.getAutoCommit();
if (valueNodes == null) {
SelectStatement select = upsert.getSelect();
assert (select != null);
select = SubselectRewriter.flatten(select, connection);
ColumnResolver selectResolver = FromCompiler.getResolverForQuery(select, connection);
select = StatementNormalizer.normalize(select, selectResolver);
select = prependTenantAndViewConstants(table, select, tenantId, addViewColumnsToBe);
sameTable =
select.getFrom().size() == 1 && tableRef.equals(selectResolver.getTables().get(0));
/* We can run the upsert in a coprocessor if:
* 1) from has only 1 table and the into table matches from table
* 2) the select query isn't doing aggregation
* 3) autoCommit is on
* 4) the table is not immutable, as the client is the one that figures out the additional
* puts for index tables.
* 5) no limit clause
* Otherwise, run the query to pull the data from the server
* and populate the MutationState (upto a limit).
*/
runOnServer =
sameTable
&& isAutoCommit
&& !table.isImmutableRows()
&& !select.isAggregate()
&& !select.isDistinct()
&& select.getLimit() == null
&& table.getBucketNum() == null;
ParallelIteratorFactory parallelIteratorFactory;
if (select.isAggregate() || select.isDistinct() || select.getLimit() != null) {
parallelIteratorFactory = null;
} else {
// We can pipeline the upsert select instead of spooling everything to disk first,
// if we don't have any post processing that's required.
parallelIteratorFactory =
upsertParallelIteratorFactoryToBe =
new UpsertingParallelIteratorFactory(connection, tableRef);
}
// If we may be able to run on the server, add a hint that favors using the data table
// if all else is equal.
// TODO: it'd be nice if we could figure out in advance if the PK is potentially changing,
// as this would disallow running on the server. We currently use the row projector we
// get back to figure this out.
HintNode hint = upsert.getHint();
if (!upsert.getHint().hasHint(Hint.USE_INDEX_OVER_DATA_TABLE)) {
hint = HintNode.create(hint, Hint.USE_DATA_OVER_INDEX_TABLE);
}
select = SelectStatement.create(select, hint);
// Pass scan through if same table in upsert and select so that projection is computed
// correctly
// Use optimizer to choose the best plan
plan =
new QueryOptimizer(services)
.optimize(statement, select, selectResolver, targetColumns, parallelIteratorFactory);
runOnServer &= plan.getTableRef().equals(tableRef);
rowProjectorToBe = plan.getProjector();
nValuesToSet = rowProjectorToBe.getColumnCount();
// Cannot auto commit if doing aggregation or topN or salted
// Salted causes problems because the row may end up living on a different region
} else {
nValuesToSet =
valueNodes.size()
+ addViewColumnsToBe.size()
+ (isTenantSpecific ? 1 : 0)
+ (isSharedViewIndex ? 1 : 0);
}
final RowProjector projector = rowProjectorToBe;
final UpsertingParallelIteratorFactory upsertParallelIteratorFactory =
upsertParallelIteratorFactoryToBe;
final QueryPlan queryPlan = plan;
// Resize down to allow a subset of columns to be specifiable
if (columnNodes.isEmpty() && columnIndexesToBe.length >= nValuesToSet) {
nColumnsToSet = nValuesToSet;
columnIndexesToBe = Arrays.copyOf(columnIndexesToBe, nValuesToSet);
pkSlotIndexesToBe = Arrays.copyOf(pkSlotIndexesToBe, nValuesToSet);
}
if (nValuesToSet != nColumnsToSet) {
throw new SQLExceptionInfo.Builder(SQLExceptionCode.UPSERT_COLUMN_NUMBERS_MISMATCH)
.setMessage(
"Numbers of columns: " + nColumnsToSet + ". Number of values: " + nValuesToSet)
.build()
.buildException();
}
final int[] columnIndexes = columnIndexesToBe;
final int[] pkSlotIndexes = pkSlotIndexesToBe;
final Set<PColumn> addViewColumns = addViewColumnsToBe;
final Set<PColumn> overlapViewColumns = overlapViewColumnsToBe;
// TODO: break this up into multiple functions
////////////////////////////////////////////////////////////////////
// UPSERT SELECT
/////////////////////////////////////////////////////////////////////
if (valueNodes == null) {
// Before we re-order, check that for updatable view columns
// the projected expression either matches the column name or
// is a constant with the same required value.
throwIfNotUpdatable(tableRef, overlapViewColumnsToBe, targetColumns, projector, sameTable);
////////////////////////////////////////////////////////////////////
// UPSERT SELECT run server-side (maybe)
/////////////////////////////////////////////////////////////////////
if (runOnServer) {
// At most this array will grow bigger by the number of PK columns
int[] allColumnsIndexes = Arrays.copyOf(columnIndexes, columnIndexes.length + nValuesToSet);
int[] reverseColumnIndexes = new int[table.getColumns().size()];
List<Expression> projectedExpressions =
Lists.newArrayListWithExpectedSize(reverseColumnIndexes.length);
Arrays.fill(reverseColumnIndexes, -1);
for (int i = 0; i < nValuesToSet; i++) {
projectedExpressions.add(projector.getColumnProjector(i).getExpression());
reverseColumnIndexes[columnIndexes[i]] = i;
}
/*
* Order projected columns and projected expressions with PK columns
* leading order by slot position
*/
int offset = table.getBucketNum() == null ? 0 : 1;
for (int i = 0; i < table.getPKColumns().size() - offset; i++) {
PColumn column = table.getPKColumns().get(i + offset);
int pos = reverseColumnIndexes[column.getPosition()];
if (pos == -1) {
// Last PK column may be fixed width and nullable
// We don't want to insert a null expression b/c
// it's not valid to set a fixed width type to null.
if (column.getDataType().isFixedWidth()) {
continue;
}
// Add literal null for missing PK columns
pos = projectedExpressions.size();
Expression literalNull =
LiteralExpression.newConstant(null, column.getDataType(), true);
projectedExpressions.add(literalNull);
allColumnsIndexes[pos] = column.getPosition();
}
// Swap select expression at pos with i
Collections.swap(projectedExpressions, i, pos);
// Swap column indexes and reverse column indexes too
int tempPos = allColumnsIndexes[i];
allColumnsIndexes[i] = allColumnsIndexes[pos];
allColumnsIndexes[pos] = tempPos;
reverseColumnIndexes[tempPos] = reverseColumnIndexes[i];
reverseColumnIndexes[i] = i;
}
// If any pk slots are changing, be conservative and don't run this server side.
// If the row ends up living in a different region, we'll get an error otherwise.
for (int i = 0; i < table.getPKColumns().size(); i++) {
PColumn column = table.getPKColumns().get(i);
Expression source = projectedExpressions.get(i);
if (source == null
|| !source.equals(
new ColumnRef(tableRef, column.getPosition()).newColumnExpression())) {
// TODO: we could check the region boundaries to see if the pk will still be in it.
runOnServer = false; // bail on running server side, since PK may be changing
break;
}
}
////////////////////////////////////////////////////////////////////
// UPSERT SELECT run server-side
/////////////////////////////////////////////////////////////////////
if (runOnServer) {
// Iterate through columns being projected
List<PColumn> projectedColumns =
Lists.newArrayListWithExpectedSize(projectedExpressions.size());
for (int i = 0; i < projectedExpressions.size(); i++) {
// Must make new column if position has changed
PColumn column = allColumns.get(allColumnsIndexes[i]);
projectedColumns.add(column.getPosition() == i ? column : new PColumnImpl(column, i));
}
// Build table from projectedColumns
PTable projectedTable = PTableImpl.makePTable(table, projectedColumns);
SelectStatement select =
SelectStatement.create(SelectStatement.COUNT_ONE, upsert.getHint());
final RowProjector aggProjector =
ProjectionCompiler.compile(queryPlan.getContext(), select, GroupBy.EMPTY_GROUP_BY);
/*
* Transfer over PTable representing subset of columns selected, but all PK columns.
* Move columns setting PK first in pkSlot order, adding LiteralExpression of null for any missing ones.
* Transfer over List<Expression> for projection.
* In region scan, evaluate expressions in order, collecting first n columns for PK and collection non PK in mutation Map
* Create the PRow and get the mutations, adding them to the batch
*/
final StatementContext context = queryPlan.getContext();
final Scan scan = context.getScan();
scan.setAttribute(
BaseScannerRegionObserver.UPSERT_SELECT_TABLE,
UngroupedAggregateRegionObserver.serialize(projectedTable));
scan.setAttribute(
BaseScannerRegionObserver.UPSERT_SELECT_EXPRS,
UngroupedAggregateRegionObserver.serialize(projectedExpressions));
// Ignore order by - it has no impact
final QueryPlan aggPlan =
new AggregatePlan(
context,
select,
tableRef,
aggProjector,
null,
OrderBy.EMPTY_ORDER_BY,
null,
GroupBy.EMPTY_GROUP_BY,
null);
return new MutationPlan() {
@Override
public PhoenixConnection getConnection() {
return connection;
}
@Override
public ParameterMetaData getParameterMetaData() {
return queryPlan.getContext().getBindManager().getParameterMetaData();
}
@Override
public StatementContext getContext() {
return queryPlan.getContext();
}
@Override
public MutationState execute() throws SQLException {
ImmutableBytesWritable ptr = context.getTempPtr();
tableRef.getTable().getIndexMaintainers(ptr);
ServerCache cache = null;
try {
if (ptr.getLength() > 0) {
IndexMetaDataCacheClient client =
new IndexMetaDataCacheClient(connection, tableRef);
cache = client.addIndexMetadataCache(context.getScanRanges(), ptr);
byte[] uuidValue = cache.getId();
scan.setAttribute(PhoenixIndexCodec.INDEX_UUID, uuidValue);
}
ResultIterator iterator = aggPlan.iterator();
try {
Tuple row = iterator.next();
final long mutationCount =
(Long) aggProjector.getColumnProjector(0).getValue(row, PDataType.LONG, ptr);
return new MutationState(maxSize, connection) {
@Override
public long getUpdateCount() {
return mutationCount;
}
};
} finally {
iterator.close();
}
} finally {
if (cache != null) {
cache.close();
}
}
}
@Override
public ExplainPlan getExplainPlan() throws SQLException {
List<String> queryPlanSteps = aggPlan.getExplainPlan().getPlanSteps();
List<String> planSteps =
Lists.newArrayListWithExpectedSize(queryPlanSteps.size() + 1);
planSteps.add("UPSERT ROWS");
planSteps.addAll(queryPlanSteps);
return new ExplainPlan(planSteps);
}
};
}
}
////////////////////////////////////////////////////////////////////
// UPSERT SELECT run client-side
/////////////////////////////////////////////////////////////////////
return new MutationPlan() {
@Override
public PhoenixConnection getConnection() {
return connection;
}
@Override
public ParameterMetaData getParameterMetaData() {
return queryPlan.getContext().getBindManager().getParameterMetaData();
}
@Override
public StatementContext getContext() {
return queryPlan.getContext();
}
@Override
public MutationState execute() throws SQLException {
ResultIterator iterator = queryPlan.iterator();
if (upsertParallelIteratorFactory == null) {
return upsertSelect(
statement, tableRef, projector, iterator, columnIndexes, pkSlotIndexes);
}
upsertParallelIteratorFactory.setRowProjector(projector);
upsertParallelIteratorFactory.setColumnIndexes(columnIndexes);
upsertParallelIteratorFactory.setPkSlotIndexes(pkSlotIndexes);
Tuple tuple;
long totalRowCount = 0;
while ((tuple = iterator.next()) != null) { // Runs query
Cell kv = tuple.getValue(0);
totalRowCount +=
PDataType.LONG
.getCodec()
.decodeLong(kv.getValueArray(), kv.getValueOffset(), SortOrder.getDefault());
}
// Return total number of rows that have been updated. In the case of auto commit being
// off
// the mutations will all be in the mutation state of the current connection.
return new MutationState(maxSize, statement.getConnection(), totalRowCount);
}
@Override
public ExplainPlan getExplainPlan() throws SQLException {
List<String> queryPlanSteps = queryPlan.getExplainPlan().getPlanSteps();
List<String> planSteps = Lists.newArrayListWithExpectedSize(queryPlanSteps.size() + 1);
planSteps.add("UPSERT SELECT");
planSteps.addAll(queryPlanSteps);
return new ExplainPlan(planSteps);
}
};
}
////////////////////////////////////////////////////////////////////
// UPSERT VALUES
/////////////////////////////////////////////////////////////////////
int nodeIndex = 0;
// initialze values with constant byte values first
final byte[][] values = new byte[nValuesToSet][];
if (isTenantSpecific) {
values[nodeIndex++] = connection.getTenantId().getBytes();
}
if (isSharedViewIndex) {
values[nodeIndex++] = MetaDataUtil.getViewIndexIdDataType().toBytes(table.getViewIndexId());
}
final int nodeIndexOffset = nodeIndex;
// Allocate array based on size of all columns in table,
// since some values may not be set (if they're nullable).
final StatementContext context = new StatementContext(statement, resolver, new Scan());
UpsertValuesCompiler expressionBuilder = new UpsertValuesCompiler(context);
final List<Expression> constantExpressions =
Lists.newArrayListWithExpectedSize(valueNodes.size());
// First build all the expressions, as with sequences we want to collect them all first
// and initialize them in one batch
for (ParseNode valueNode : valueNodes) {
if (!valueNode.isStateless()) {
throw new SQLExceptionInfo.Builder(SQLExceptionCode.VALUE_IN_UPSERT_NOT_CONSTANT)
.build()
.buildException();
}
PColumn column = allColumns.get(columnIndexes[nodeIndex]);
expressionBuilder.setColumn(column);
Expression expression = valueNode.accept(expressionBuilder);
if (expression.getDataType() != null
&& !expression.getDataType().isCastableTo(column.getDataType())) {
throw TypeMismatchException.newException(
expression.getDataType(),
column.getDataType(),
"expression: " + expression.toString() + " in column " + column);
}
constantExpressions.add(expression);
nodeIndex++;
}
return new MutationPlan() {
@Override
public PhoenixConnection getConnection() {
return connection;
}
@Override
public ParameterMetaData getParameterMetaData() {
return context.getBindManager().getParameterMetaData();
}
@Override
public StatementContext getContext() {
return context;
}
@Override
public MutationState execute() throws SQLException {
ImmutableBytesWritable ptr = context.getTempPtr();
final SequenceManager sequenceManager = context.getSequenceManager();
// Next evaluate all the expressions
int nodeIndex = nodeIndexOffset;
Tuple tuple =
sequenceManager.getSequenceCount() == 0 ? null : sequenceManager.newSequenceTuple(null);
for (Expression constantExpression : constantExpressions) {
PColumn column = allColumns.get(columnIndexes[nodeIndex]);
constantExpression.evaluate(tuple, ptr);
Object value = null;
if (constantExpression.getDataType() != null) {
value =
constantExpression
.getDataType()
.toObject(
ptr,
constantExpression.getSortOrder(),
constantExpression.getMaxLength(),
constantExpression.getScale());
if (!constantExpression.getDataType().isCoercibleTo(column.getDataType(), value)) {
throw TypeMismatchException.newException(
constantExpression.getDataType(),
column.getDataType(),
"expression: " + constantExpression.toString() + " in column " + column);
}
if (!column
.getDataType()
.isSizeCompatible(
ptr,
value,
constantExpression.getDataType(),
constantExpression.getMaxLength(),
constantExpression.getScale(),
column.getMaxLength(),
column.getScale())) {
throw new SQLExceptionInfo.Builder(SQLExceptionCode.DATA_EXCEEDS_MAX_CAPACITY)
.setColumnName(column.getName().getString())
.setMessage("value=" + constantExpression.toString())
.build()
.buildException();
}
}
column
.getDataType()
.coerceBytes(
ptr,
value,
constantExpression.getDataType(),
constantExpression.getMaxLength(),
constantExpression.getScale(),
constantExpression.getSortOrder(),
column.getMaxLength(),
column.getScale(),
column.getSortOrder());
if (overlapViewColumns.contains(column)
&& Bytes.compareTo(
ptr.get(),
ptr.getOffset(),
ptr.getLength(),
column.getViewConstant(),
0,
column.getViewConstant().length - 1)
!= 0) {
throw new SQLExceptionInfo.Builder(SQLExceptionCode.CANNOT_UPDATE_VIEW_COLUMN)
.setColumnName(column.getName().getString())
.setMessage("value=" + constantExpression.toString())
.build()
.buildException();
}
values[nodeIndex] = ByteUtil.copyKeyBytesIfNecessary(ptr);
nodeIndex++;
}
// Add columns based on view
for (PColumn column : addViewColumns) {
if (IndexUtil.getViewConstantValue(column, ptr)) {
values[nodeIndex++] = ByteUtil.copyKeyBytesIfNecessary(ptr);
} else {
throw new IllegalStateException();
}
}
Map<ImmutableBytesPtr, Map<PColumn, byte[]>> mutation = Maps.newHashMapWithExpectedSize(1);
setValues(values, pkSlotIndexes, columnIndexes, tableRef.getTable(), mutation);
return new MutationState(tableRef, mutation, 0, maxSize, connection);
}
@Override
public ExplainPlan getExplainPlan() throws SQLException {
List<String> planSteps = Lists.newArrayListWithExpectedSize(2);
if (context.getSequenceManager().getSequenceCount() > 0) {
planSteps.add(
"CLIENT RESERVE " + context.getSequenceManager().getSequenceCount() + " SEQUENCES");
}
planSteps.add("PUT SINGLE ROW");
return new ExplainPlan(planSteps);
}
};
}
/**
* Order the plans among all the possible ones from best to worst. Since we don't keep stats yet,
* we use the following simple algorithm: 1) If the query is a point lookup (i.e. we have a set of
* exact row keys), choose among those. 2) If the query has an ORDER BY and a LIMIT, choose the
* plan that has all the ORDER BY expression in the same order as the row key columns. 3) If there
* are more than one plan that meets (1&2), choose the plan with: a) the most row key columns that
* may be used to form the start/stop scan key. b) the plan that preserves ordering for a group
* by. c) the data table plan
*
* @param plans the list of candidate plans
* @return list of plans ordered from best to worst.
*/
private List<QueryPlan> orderPlansBestToWorst(
SelectStatement select, List<QueryPlan> plans, boolean stopAtBestPlan) {
final QueryPlan dataPlan = plans.get(0);
if (plans.size() == 1) {
return plans;
}
/**
* If we have a plan(s) that are just point lookups (i.e. fully qualified row keys), then favor
* those first.
*/
List<QueryPlan> candidates = Lists.newArrayListWithExpectedSize(plans.size());
if (stopAtBestPlan) { // If we're stopping at the best plan, only consider point lookups if
// there are any
for (QueryPlan plan : plans) {
if (plan.getContext().getScanRanges().isPointLookup()) {
candidates.add(plan);
}
}
} else {
candidates.addAll(plans);
}
/**
* If we have a plan(s) that removes the order by, choose from among these, as this is typically
* the most expensive operation. Once we have stats, if there's a limit on the query, we might
* choose a different plan. For example if the limit was a very large number and the combination
* of applying other filters on the row key are estimated to choose fewer rows, we'd choose that
* one.
*/
List<QueryPlan> stillCandidates = plans;
List<QueryPlan> bestCandidates = candidates;
if (!candidates.isEmpty()) {
stillCandidates = candidates;
bestCandidates = Lists.<QueryPlan>newArrayListWithExpectedSize(candidates.size());
}
for (QueryPlan plan : stillCandidates) {
// If ORDER BY optimized out (or not present at all)
if (plan.getOrderBy().getOrderByExpressions().isEmpty()) {
bestCandidates.add(plan);
}
}
if (bestCandidates.isEmpty()) {
bestCandidates.addAll(stillCandidates);
}
int nViewConstants = 0;
PTable dataTable = dataPlan.getTableRef().getTable();
if (dataTable.getType() == PTableType.VIEW) {
for (PColumn column : dataTable.getColumns()) {
if (column.getViewConstant() != null) {
nViewConstants++;
}
}
}
final int boundRanges = nViewConstants;
final int comparisonOfDataVersusIndexTable =
select.getHint().hasHint(Hint.USE_DATA_OVER_INDEX_TABLE) ? -1 : 1;
Collections.sort(
bestCandidates,
new Comparator<QueryPlan>() {
@Override
public int compare(QueryPlan plan1, QueryPlan plan2) {
PTable table1 = plan1.getTableRef().getTable();
PTable table2 = plan2.getTableRef().getTable();
// For shared indexes (i.e. indexes on views and local indexes),
// a) add back any view constants as these won't be in the index, and
// b) ignore the viewIndexId which will be part of the row key columns.
int c =
(plan2.getContext().getScanRanges().getBoundPkColumnCount()
+ (table2.getViewIndexId() == null ? 0 : (boundRanges - 1)))
- (plan1.getContext().getScanRanges().getBoundPkColumnCount()
+ (table1.getViewIndexId() == null ? 0 : (boundRanges - 1)));
if (c != 0) return c;
if (plan1.getGroupBy() != null && plan2.getGroupBy() != null) {
if (plan1.getGroupBy().isOrderPreserving()
!= plan2.getGroupBy().isOrderPreserving()) {
return plan1.getGroupBy().isOrderPreserving() ? -1 : 1;
}
}
// Use smaller table (table with fewest kv columns)
c =
(table1.getColumns().size() - table1.getPKColumns().size())
- (table2.getColumns().size() - table2.getPKColumns().size());
if (c != 0) return c;
// If all things are equal, don't choose local index as it forces scan
// on every region (unless there's no start/stop key)
if (table1.getIndexType() == IndexType.LOCAL) {
return plan1.getContext().getScanRanges().getRanges().isEmpty() ? -1 : 1;
}
if (table2.getIndexType() == IndexType.LOCAL) {
return plan2.getContext().getScanRanges().getRanges().isEmpty() ? 1 : -1;
}
// All things being equal, just use the table based on the
// Hint.USE_DATA_OVER_INDEX_TABLE
if (table1.getType() == PTableType.INDEX) {
return comparisonOfDataVersusIndexTable;
}
if (table2.getType() == PTableType.INDEX) {
return -comparisonOfDataVersusIndexTable;
}
return 0;
}
});
return bestCandidates;
}