pack-priv Class RowResultSetNode

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.addNewPredicate.

Add a new predicate to the list. This is useful when doing subquery transformations, when we build a new predicate with the left side of the subquery operator and the subquery's result column.

Parameters

predicate:Predicate

The predicate to add

Returns:ResultSetNode

ResultSetNode The new top of the tree.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.adjustForSortElimination.

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.adjustForSortElimination.

Notify the underlying result set tree that the optimizer has chosen to "eliminate" a sort. Sort elimination can happen as part of preprocessing (see esp. SelectNode.preprocess(...)) or it can happen if the optimizer chooses an access path that inherently returns the rows in the correct order (also known as a "sort avoidance" plan). In either case we drop the sort and rely on the underlying result set tree to return its rows in the correct order. For most types of ResultSetNodes we automatically get the rows in the correct order if the sort was eliminated. One exception to this rule, though, is the case of an IndexRowToBaseRowNode, for which we have to disable bulk fetching on the underlying base table. Otherwise the index scan could return rows out of order if the base table is updated while the scan is "in progress" (i.e. while the result set is open). In order to account for this (and potentially other, similar issues in the future) this method exists to notify the result set node that it is expected to return rows in the correct order. The result set can then take necessary action to satsify this requirement--such as disabling bulk fetch in the case of IndexRowToBaseRowNode. All of that said, any ResultSetNodes for which we could potentially eliminate sorts should override this method accordingly. So we don't ever expect to get here.

Annotations

@Override

See Also

ResultSetNode#adjustForSortElimination

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.bindExpressions.

Bind the expressions in this RowResultSetNode. This means binding the sub-expressions, as well as figuring out what the return type is for each expression.

Parameters

fromListParam:FromList

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.bindExpressions.

FromList to use/append to.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.bindExpressionsWithTables.

Bind the expressions in this ResultSetNode if it has tables. This means binding the sub-expressions, as well as figuring out what the return type is for each expression.

Parameters

fromListParam:FromList

FromList to use/append to.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.bindNonVTITables.

Bind the non VTI tables in this ResultSetNode. This includes getting their descriptors from the data dictionary and numbering them.

Parameters

dataDictionary:DataDictionary

The DataDictionary to use for binding

fromListParam:FromList

FromList to use/append to.

Returns:ResultSetNode

ResultSetNode

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.bindTargetExpressions.

Bind the expressions in the target list. This means binding the sub-expressions, as well as figuring out what the return type is for each expression. This is useful for EXISTS subqueries, where we need to validate the target list before blowing it away and replacing it with a SELECT true.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.bindUntypedNullsToResultColumns.

Bind any untyped null nodes to the types in the given ResultColumnList.

Parameters

bindingRCL:ResultColumnList

The ResultColumnList with the types to bind to.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.enhanceRCLForInsert.

Modify the RCL of this node to match the target of the insert.

Parameters

target:InsertNode

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.enhanceRCLForInsert.

the target node for the insert

inOrder:boolean

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.enhanceRCLForInsert.

are source cols in same order as target cols?

colMap:int[]

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.enhanceRCLForInsert.

int array representation of correspondence between RCLs - colmap[i] = -1 -> missing in current RCL colmap[i] = j -> targetRCL(i) <-> thisRCL(j+1)

Returns:ResultSetNode

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.enhanceRCLForInsert.

a node that replaces this node and whose RCL matches the target RCL. May return this node if no changes to the RCL are needed, or if the RCL is modified in-place.

Annotations

@Override

Exceptions

StandardException:

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.enhanceRCLForInsert.

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.ensurePredicateList.

Ensure that the top of the RSN tree has a PredicateList.

Parameters

numTables:int

The number of tables in the query.

Returns:ResultSetNode

ResultSetNode A RSN tree with a node which has a PredicateList on top.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.flattenableInFromSubquery.

Evaluate whether or not the subquery in a FromSubquery is flattenable. Currently, a FSqry is flattenable if all of the following are true: o Subquery is a SelectNode or a RowResultSetNode (not a UnionNode) o It contains no top level subqueries. (RESOLVE - we can relax this) o It does not contain a group by or having clause o It does not contain aggregates. o There is at least one result set in the from list that is not a RowResultSetNode (the reason is to avoid having an outer SelectNode with an empty FromList.

Parameters

fromList:FromList

The outer from list

Returns:boolean

boolean Whether or not the FromSubquery is flattenable.

Annotations

@Override

Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.generate.

The generated ResultSet will be: RowResultSet -- for the VALUES clause

Parameters

acb:ActivationClassBuilder

Doc from org.apache.derby.impl.sql.compile.QueryTreeNode.generate.

The ActivationClassBuilder for the class being built

mb:MethodBuilder

Doc from org.apache.derby.impl.sql.compile.QueryTreeNode.generate.

The method for the generated code to go into

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.FromTable.getExposedName.

Get the exposed name for this table, which is the name that can be used to refer to it in the rest of the query.

Returns:String

The exposed name of this table.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.getMatchingColumn.

Try to find a ResultColumn in the table represented by this FromTable that matches the name in the given ColumnReference.

Parameters

columnReference:ColumnReference

The columnReference whose name we're looking for in the given table.

Returns:ResultColumn

A ResultColumn whose expression is the ColumnNode that matches the ColumnReference. Returns null if there is no match.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.modifyAccessPaths.

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.modifyAccessPaths.

Modify the access paths according to the decisions the optimizer made. This can include adding project/restrict nodes, index-to-base-row nodes, etc.

Returns:ResultSetNode

The modified query tree

Annotations

@Override

Exceptions

StandardException:

Thrown on error

See Also

ResultSetNode#modifyAccessPaths

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.optimize.

Optimize this SelectNode. This means choosing the best access path for each table, among other things.

Parameters

dataDictionary:DataDictionary

The DataDictionary to use for optimization

predicateList:PredicateList

The predicate list to optimize against

outerRows:double

The number of outer joining rows

Returns:ResultSetNode

ResultSetNode The top of the optimized tree

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.FromTable.optimizeSubqueries.

Optimize any subqueries that haven't been optimized any where else. This is useful for a RowResultSetNode as a derived table because it doesn't get optimized otherwise.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.preprocess.

Put a ProjectRestrictNode on top of each FromTable in the FromList. ColumnReferences must continue to point to the same ResultColumn, so that ResultColumn must percolate up to the new PRN. However, that ResultColumn will point to a new expression, a VirtualColumnNode, which points to the FromTable and the ResultColumn that is the source for the ColumnReference. (The new PRN will have the original of the ResultColumnList and the ResultColumns from that list. The FromTable will get shallow copies of the ResultColumnList and its ResultColumns. ResultColumn.expression will remain at the FromTable, with the PRN getting a new VirtualColumnNode for each ResultColumn.expression.) We then project out the non-referenced columns. If there are no referenced columns, then the PRN's ResultColumnList will consist of a single ResultColumn whose expression is 1.

Parameters

numTables:int

Number of tables in the DML Statement

gbl:GroupByList

The group by list, if any

fromList:FromList

The from list, if any

Returns:ResultSetNode

The generated ProjectRestrictNode atop the original FromTable.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.printSubNodes.

Prints the sub-nodes of this object. See QueryTreeNode.java for how tree printing is supposed to work.

Parameters

depth:int

The depth of this node in the tree

Annotations

@Override

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.pushOffsetFetchFirst.

Push down the offset and fetch first parameters, if any, to this node.

Parameters

offset:ValueNode

the OFFSET, if any

fetchFirst:ValueNode

the OFFSET FIRST, if any

hasJDBClimitClause:boolean

true if the clauses were added by (and have the semantics of) a JDBC limit clause

Annotations

@Override

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.pushOrderByList.

Push the order by list down from the cursor node into its child result set so that the optimizer has all of the information that it needs to consider sort avoidance.

Parameters

orderByList:OrderByList

The order by list

Annotations

@Override

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.replaceOrForbidDefaults.

Doc from org.apache.derby.impl.sql.compile.ResultSetNode.replaceOrForbidDefaults.

Replace any DEFAULTs with the associated tree for the default if allowed, or flag (when inside top level set operator nodes). Subqueries are checked for illegal DEFAULTs elsewhere.

Parameters

ttd:TableDescriptor

The TableDescriptor for the target table.

tcl:ResultColumnList

The RCL for the target table.

allowDefaults:boolean

true if allowed

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.returnsAtMostOneRow.

Return whether or not this ResultSet tree is guaranteed to return at most 1 row based on heuristics. (A RowResultSetNode and a SELECT with a non-grouped aggregate will return at most 1 row.)

Returns:boolean

Whether or not this ResultSet tree is guaranteed to return at most 1 row based on heuristics.

Annotations

@Override

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.setTableConstructorTypes.

Set the type of each parameter in the result column list for this table constructor.

Parameters

typeColumns:ResultColumnList

The ResultColumnList containing the desired result types.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ResultSetNode.verifySelectStarSubquery.

Verify that a SELECT * is valid for this type of subquery.

Parameters

outerFromList:FromList

The FromList from the outer query block(s)

subqueryType:int

The subquery type

Annotations

@Override

Exceptions

StandardException:

Thrown on error