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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cassandra.cql3.statements;
import java.util.*;
import java.util.stream.Collectors;
import com.google.common.collect.Iterables;
import org.apache.cassandra.auth.Permission;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.config.ColumnDefinition;
import org.apache.cassandra.config.Schema;
import org.apache.cassandra.config.ViewDefinition;
import org.apache.cassandra.cql3.*;
import org.apache.cassandra.cql3.restrictions.StatementRestrictions;
import org.apache.cassandra.cql3.selection.RawSelector;
import org.apache.cassandra.cql3.selection.Selectable;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.db.marshal.ReversedType;
import org.apache.cassandra.db.view.View;
import org.apache.cassandra.exceptions.AlreadyExistsException;
import org.apache.cassandra.exceptions.InvalidRequestException;
import org.apache.cassandra.exceptions.RequestValidationException;
import org.apache.cassandra.exceptions.UnauthorizedException;
import org.apache.cassandra.schema.TableParams;
import org.apache.cassandra.service.ClientState;
import org.apache.cassandra.service.ClientWarn;
import org.apache.cassandra.service.MigrationManager;
import org.apache.cassandra.thrift.ThriftValidation;
import org.apache.cassandra.transport.Event;
public class CreateViewStatement extends SchemaAlteringStatement
{
private final CFName baseName;
private final List<RawSelector> selectClause;
private final WhereClause whereClause;
private final List<ColumnIdentifier.Raw> partitionKeys;
private final List<ColumnIdentifier.Raw> clusteringKeys;
public final CFProperties properties = new CFProperties();
private final boolean ifNotExists;
public CreateViewStatement(CFName viewName,
CFName baseName,
List<RawSelector> selectClause,
WhereClause whereClause,
List<ColumnIdentifier.Raw> partitionKeys,
List<ColumnIdentifier.Raw> clusteringKeys,
boolean ifNotExists)
{
super(viewName);
this.baseName = baseName;
this.selectClause = selectClause;
this.whereClause = whereClause;
this.partitionKeys = partitionKeys;
this.clusteringKeys = clusteringKeys;
this.ifNotExists = ifNotExists;
}
public void checkAccess(ClientState state) throws UnauthorizedException, InvalidRequestException
{
if (!baseName.hasKeyspace())
baseName.setKeyspace(keyspace(), true);
state.hasColumnFamilyAccess(keyspace(), baseName.getColumnFamily(), Permission.ALTER);
}
public void validate(ClientState state) throws RequestValidationException
{
// We do validation in announceMigration to reduce doubling up of work
}
private interface AddColumn {
void add(ColumnIdentifier identifier, AbstractType<?> type);
}
private void add(CFMetaData baseCfm, Iterable<ColumnIdentifier> columns, AddColumn adder)
{
for (ColumnIdentifier column : columns)
{
AbstractType<?> type = baseCfm.getColumnDefinition(column).type;
if (properties.definedOrdering.containsKey(column))
{
boolean desc = properties.definedOrdering.get(column);
if (!desc && type.isReversed())
{
type = ((ReversedType)type).baseType;
}
else if (desc && !type.isReversed())
{
type = ReversedType.getInstance(type);
}
}
adder.add(column, type);
}
}
public Event.SchemaChange announceMigration(boolean isLocalOnly) throws RequestValidationException
{
// We need to make sure that:
// - primary key includes all columns in base table's primary key
// - make sure that the select statement does not have anything other than columns
// and their names match the base table's names
// - make sure that primary key does not include any collections
// - make sure there is no where clause in the select statement
// - make sure there is not currently a table or view
// - make sure baseTable gcGraceSeconds > 0
properties.validate();
if (properties.useCompactStorage)
throw new InvalidRequestException("Cannot use 'COMPACT STORAGE' when defining a materialized view");
// We enforce the keyspace because if the RF is different, the logic to wait for a
// specific replica would break
if (!baseName.getKeyspace().equals(keyspace()))
throw new InvalidRequestException("Cannot create a materialized view on a table in a separate keyspace");
CFMetaData cfm = ThriftValidation.validateColumnFamily(baseName.getKeyspace(), baseName.getColumnFamily());
if (cfm.isCounter())
throw new InvalidRequestException("Materialized views are not supported on counter tables");
if (cfm.isView())
throw new InvalidRequestException("Materialized views cannot be created against other materialized views");
if (cfm.params.gcGraceSeconds == 0)
{
throw new InvalidRequestException(String.format("Cannot create materialized view '%s' for base table " +
"'%s' with gc_grace_seconds of 0, since this value is " +
"used to TTL undelivered updates. Setting gc_grace_seconds" +
" too low might cause undelivered updates to expire " +
"before being replayed.", cfName.getColumnFamily(),
baseName.getColumnFamily()));
}
Set<ColumnIdentifier> included = new HashSet<>();
for (RawSelector selector : selectClause)
{
Selectable.Raw selectable = selector.selectable;
if (selectable instanceof Selectable.WithFieldSelection.Raw)
throw new InvalidRequestException("Cannot select out a part of type when defining a materialized view");
if (selectable instanceof Selectable.WithFunction.Raw)
throw new InvalidRequestException("Cannot use function when defining a materialized view");
if (selectable instanceof Selectable.WritetimeOrTTL.Raw)
throw new InvalidRequestException("Cannot use function when defining a materialized view");
ColumnIdentifier identifier = (ColumnIdentifier) selectable.prepare(cfm);
if (selector.alias != null)
throw new InvalidRequestException(String.format("Cannot alias column '%s' as '%s' when defining a materialized view", identifier.toString(), selector.alias.toString()));
ColumnDefinition cdef = cfm.getColumnDefinition(identifier);
if (cdef == null)
throw new InvalidRequestException("Unknown column name detected in CREATE MATERIALIZED VIEW statement : "+identifier);
included.add(identifier);
}
Set<ColumnIdentifier.Raw> targetPrimaryKeys = new HashSet<>();
for (ColumnIdentifier.Raw identifier : Iterables.concat(partitionKeys, clusteringKeys))
{
if (!targetPrimaryKeys.add(identifier))
throw new InvalidRequestException("Duplicate entry found in PRIMARY KEY: "+identifier);
ColumnDefinition cdef = cfm.getColumnDefinition(identifier.prepare(cfm));
if (cdef == null)
throw new InvalidRequestException("Unknown column name detected in CREATE MATERIALIZED VIEW statement : "+identifier);
if (cfm.getColumnDefinition(identifier.prepare(cfm)).type.isMultiCell())
throw new InvalidRequestException(String.format("Cannot use MultiCell column '%s' in PRIMARY KEY of materialized view", identifier));
if (cdef.isStatic())
throw new InvalidRequestException(String.format("Cannot use Static column '%s' in PRIMARY KEY of materialized view", identifier));
}
// build the select statement
Map<ColumnIdentifier.Raw, Boolean> orderings = Collections.emptyMap();
SelectStatement.Parameters parameters = new SelectStatement.Parameters(orderings, false, true, false);
SelectStatement.RawStatement rawSelect = new SelectStatement.RawStatement(baseName, parameters, selectClause, whereClause, null);
ClientState state = ClientState.forInternalCalls();
state.setKeyspace(keyspace());
rawSelect.prepareKeyspace(state);
rawSelect.setBoundVariables(getBoundVariables());
ParsedStatement.Prepared prepared = rawSelect.prepare(true);
SelectStatement select = (SelectStatement) prepared.statement;
StatementRestrictions restrictions = select.getRestrictions();
if (!prepared.boundNames.isEmpty())
throw new InvalidRequestException("Cannot use query parameters in CREATE MATERIALIZED VIEW statements");
if (!restrictions.nonPKRestrictedColumns(false).isEmpty())
{
throw new InvalidRequestException(String.format(
"Non-primary key columns cannot be restricted in the SELECT statement used for materialized view " +
"creation (got restrictions on: %s)",
restrictions.nonPKRestrictedColumns(false).stream().map(def -> def.name.toString()).collect(Collectors.joining(", "))));
}
String whereClauseText = View.relationsToWhereClause(whereClause.relations);
Set<ColumnIdentifier> basePrimaryKeyCols = new HashSet<>();
for (ColumnDefinition definition : Iterables.concat(cfm.partitionKeyColumns(), cfm.clusteringColumns()))
basePrimaryKeyCols.add(definition.name);
List<ColumnIdentifier> targetClusteringColumns = new ArrayList<>();
List<ColumnIdentifier> targetPartitionKeys = new ArrayList<>();
// This is only used as an intermediate state; this is to catch whether multiple non-PK columns are used
boolean hasNonPKColumn = false;
for (ColumnIdentifier.Raw raw : partitionKeys)
hasNonPKColumn |= getColumnIdentifier(cfm, basePrimaryKeyCols, hasNonPKColumn, raw, targetPartitionKeys, restrictions);
for (ColumnIdentifier.Raw raw : clusteringKeys)
hasNonPKColumn |= getColumnIdentifier(cfm, basePrimaryKeyCols, hasNonPKColumn, raw, targetClusteringColumns, restrictions);
// We need to include all of the primary key columns from the base table in order to make sure that we do not
// overwrite values in the view. We cannot support "collapsing" the base table into a smaller number of rows in
// the view because if we need to generate a tombstone, we have no way of knowing which value is currently being
// used in the view and whether or not to generate a tombstone. In order to not surprise our users, we require
// that they include all of the columns. We provide them with a list of all of the columns left to include.
boolean missingClusteringColumns = false;
StringBuilder columnNames = new StringBuilder();
List<ColumnIdentifier> includedColumns = new ArrayList<>();
for (ColumnDefinition def : cfm.allColumns())
{
ColumnIdentifier identifier = def.name;
boolean includeDef = included.isEmpty() || included.contains(identifier);
if (includeDef && def.isStatic())
{
throw new InvalidRequestException(String.format("Unable to include static column '%s' which would be included by Materialized View SELECT * statement", identifier));
}
if (includeDef && !targetClusteringColumns.contains(identifier) && !targetPartitionKeys.contains(identifier))
{
includedColumns.add(identifier);
}
if (!def.isPrimaryKeyColumn()) continue;
if (!targetClusteringColumns.contains(identifier) && !targetPartitionKeys.contains(identifier))
{
if (missingClusteringColumns)
columnNames.append(',');
else
missingClusteringColumns = true;
columnNames.append(identifier);
}
}
if (missingClusteringColumns)
throw new InvalidRequestException(String.format("Cannot create Materialized View %s without primary key columns from base %s (%s)",
columnFamily(), baseName.getColumnFamily(), columnNames.toString()));
if (targetPartitionKeys.isEmpty())
throw new InvalidRequestException("Must select at least a column for a Materialized View");
if (targetClusteringColumns.isEmpty())
throw new InvalidRequestException("No columns are defined for Materialized View other than primary key");
CFMetaData.Builder cfmBuilder = CFMetaData.Builder.createView(keyspace(), columnFamily());
add(cfm, targetPartitionKeys, cfmBuilder::addPartitionKey);
add(cfm, targetClusteringColumns, cfmBuilder::addClusteringColumn);
add(cfm, includedColumns, cfmBuilder::addRegularColumn);
cfmBuilder.withId(properties.properties.getId());
TableParams params = properties.properties.asNewTableParams();
CFMetaData viewCfm = cfmBuilder.build().params(params);
ViewDefinition definition = new ViewDefinition(keyspace(),
columnFamily(),
Schema.instance.getId(keyspace(), baseName.getColumnFamily()),
baseName.getColumnFamily(),
included.isEmpty(),
rawSelect,
whereClauseText,
viewCfm);
try
{
MigrationManager.announceNewView(definition, isLocalOnly);
return new Event.SchemaChange(Event.SchemaChange.Change.CREATED, Event.SchemaChange.Target.TABLE, keyspace(), columnFamily());
}
catch (AlreadyExistsException e)
{
if (ifNotExists)
return null;
throw e;
}
}
private static boolean getColumnIdentifier(CFMetaData cfm,
Set<ColumnIdentifier> basePK,
boolean hasNonPKColumn,
ColumnIdentifier.Raw raw,
List<ColumnIdentifier> columns,
StatementRestrictions restrictions)
{
ColumnIdentifier identifier = raw.prepare(cfm);
ColumnDefinition def = cfm.getColumnDefinition(identifier);
boolean isPk = basePK.contains(identifier);
if (!isPk && hasNonPKColumn)
throw new InvalidRequestException(String.format("Cannot include more than one non-primary key column '%s' in materialized view primary key", identifier));
// We don't need to include the "IS NOT NULL" filter on a non-composite partition key
// because we will never allow a single partition key to be NULL
boolean isSinglePartitionKey = cfm.getColumnDefinition(identifier).isPartitionKey()
&& cfm.partitionKeyColumns().size() == 1;
if (!isSinglePartitionKey && !restrictions.isRestricted(def))
throw new InvalidRequestException(String.format("Primary key column '%s' is required to be filtered by 'IS NOT NULL'", identifier));
columns.add(identifier);
return !isPk;
}
}