internal ColumnStatistics(Variable var)
{
if (var == null)
throw new ArgumentNullException("var");
this.var = var;
divisionPoints = new SqlObject[DivisionPointCount];
}
public AliasVariableNameExpression(Expression child, Variable alias, SqlType returnType)
: base(ExpressionType.AliasVariableName)
{
SetArgument("alias", alias);
SetArgument("child", child);
if (returnType != null)
SetArgument("return_type", returnType);
}
protected override void OnVariableDropped(Variable variable)
{
// We should never come to this ...
if (executeContext.HasArgument(variable.Name)) {
throw new InvalidOperationException();
}
base.OnVariableDropped(variable);
}
protected override void OnVariableDefined(Variable variable)
{
if (executeContext.HasArgument(variable.Name)) {
VariableManager.DropVariable(variable.Name);
throw new InvalidOperationException();
}
base.OnVariableDefined(variable);
}
public void DefineVariable(VariableInfo variableInfo)
{
if (variableInfo == null)
throw new ArgumentNullException("variableInfo");
if (variables.ContainsKey(variableInfo.VariableName))
throw new ArgumentException();
var variable = new Variable(variableInfo);
variables[variableInfo.VariableName] = variable;
Scope.OnVariableDefined(variable);
}
void IVariableScope.OnVariableDropped(Variable variable)
{
if (variable.Name.Equals(TransactionSettingKeys.CurrentSchema, StringComparison.OrdinalIgnoreCase)) {
currentSchema = Database.DatabaseContext.DefaultSchema();
} else if (variable.Name.Equals(TransactionSettingKeys.ReadOnly, StringComparison.OrdinalIgnoreCase)) {
readOnly = dbReadOnly;
} else if (variable.Name.Equals(TransactionSettingKeys.IgnoreIdentifiersCase, StringComparison.OrdinalIgnoreCase)) {
ignoreCase = Database.DatabaseContext.IgnoreIdentifiersCase();
} else if (variable.Name.Equals(TransactionSettingKeys.AutoCommit, StringComparison.OrdinalIgnoreCase)) {
autoCommit = Database.DatabaseContext.AutoCommit();
} else if (variable.Name.Equals(TransactionSettingKeys.ParameterStyle, StringComparison.OrdinalIgnoreCase)) {
// TODO: Get it from the configuration...
parameterStyle = null;
}
}
public FetchVariableExpression(Variable var)
: base(ExpressionType.FetchVariable)
{
SetArgument("var", var);
}
void IVariableScope.OnVariableDefined(Variable variable)
{
if (variable.Name.Equals(TransactionSettingKeys.CurrentSchema, StringComparison.OrdinalIgnoreCase)) {
currentSchema = variable.Value;
} else if (variable.Name.Equals(TransactionSettingKeys.ReadOnly, StringComparison.OrdinalIgnoreCase)) {
if (dbReadOnly)
throw new InvalidOperationException("The database is read-only: cannot change access of the transaction.");
// TODO: handle special cases like "ON", "OFF", "ENABLE" and "DISABLE"
readOnly = variable.Value;
} else if (variable.Name.Equals(TransactionSettingKeys.IgnoreIdentifiersCase, StringComparison.OrdinalIgnoreCase)) {
ignoreCase = variable.Value;
} else if (variable.Name.Equals(TransactionSettingKeys.AutoCommit, StringComparison.OrdinalIgnoreCase)) {
autoCommit = variable.Value;
} else if (variable.Name.Equals(TransactionSettingKeys.ParameterStyle, StringComparison.OrdinalIgnoreCase)) {
parameterStyle = variable.Value;
}
}
private bool GlobMatch(string globString, Variable v)
{
// TODO: case insensitive qualification (globString may be variable case
// however table_name and col_name is information directly from the
// current metadata)
if (globString.Equals("*"))
return true;
// Must be something.*
string tableName = globString.Substring(0, globString.Length - 2);
// The table name to resolve against
TableName searchTableName = TableName.Resolve(tableName);
searchTableName = searchTableName.ResolveSchema(transaction.CurrentSchema);
return searchTableName.Equals(v.TableName);
}
private Expression RemapTables(Expression joinGraph, int[] uniqueId, IDictionary<Variable, Variable> varRemap)
{
// Exit early if join graph is null
if (joinGraph == null)
return joinGraph;
bool makeAlias = false;
TableName newName;
if (joinGraph is JoinExpression) {
JoinExpression joinExp = (JoinExpression)joinGraph;
// Search the left and right for matching terms
joinExp.Left = RemapTables(joinExp.Left, uniqueId, varRemap);
joinExp.Right = RemapTables(joinExp.Right, uniqueId, varRemap);
return joinGraph;
}
if (joinGraph is FetchTableExpression) {
// The new name of this
int un_id = uniqueId[0];
newName = new TableName("#TT" + un_id);
makeAlias = true;
} else if (joinGraph is AliasTableNameExpression) {
// The new name of this
int un_id = uniqueId[0];
newName = new TableName("#TT" + un_id);
} else if (joinGraph is SelectExpression) {
newName = ((SelectExpression)joinGraph).UniqueName;
makeAlias = true;
} else {
return joinGraph;
}
// If this is an alias table name then we need to promote the aliased
// information to the child if it's a nested query
if (joinGraph is AliasTableNameExpression) {
AliasTableNameExpression aliasExp = (AliasTableNameExpression)joinGraph;
// The child
Expression child = aliasExp.Child;
// If the child is a nested query
if (child is SelectExpression) {
SelectExpression selectExp = (SelectExpression)child;
// Promote the old aliased information
// The current alias name
TableName curAliasName = aliasExp.Alias;
// Get the output from the select and update the info
int sz = selectExp.Output.Count;
for (int i = 0; i < sz; ++i) {
SelectOutput outExp = selectExp.Output[i];
if (outExp.Expression is AliasVariableNameExpression) {
AliasVariableNameExpression varAliasExp = (AliasVariableNameExpression)outExp.Expression;
Variable oldVar = varAliasExp.Alias;
Variable newVar = new Variable(curAliasName, oldVar.Name);
varAliasExp.Alias = newVar;
} else {
throw new ApplicationException("Expected alias.");
}
}
// The new name of this alias is the unique name of the table
newName = selectExp.UniqueName;
}
}
// The list of all vars referencable from this operation
List<FetchVariableExpression> allRefs = new List<FetchVariableExpression>();
PopulateVariables(allRefs, joinGraph);
// Map them to new values,
int colr = 0;
foreach (FetchVariableExpression varExp in allRefs) {
Variable v = varExp.Variable;
varRemap[v] = new Variable(newName, v.Name);
++colr;
}
// Rename the alias,
++uniqueId[0];
if (makeAlias) {
joinGraph = new AliasTableNameExpression(joinGraph, newName);
} else {
((AliasTableNameExpression)joinGraph).Alias = newName;
}
return joinGraph;
}
/// <summary>
/// Sets this <see cref="Variable"/> object with information
/// from the given <see cref="Variable"/>.
/// </summary>
/// <param name="from"></param>
/// <returns></returns>
public Variable Set(Variable from)
{
table_name = from.table_name;
column_name = from.column_name;
return this;
}
public AliasVariableNameExpression(Expression child, Variable alias)
: this(child, alias, null)
{
}
private ITable FetchVariable(Variable var)
{
return ResultTable(new SqlObject[] { GetValue(var.Name) });
}
private Variable MakeBooleanVariable(string name, bool value)
{
var variable = new Variable(new VariableInfo(name, PrimitiveTypes.Boolean(), false));
variable.SetValue(DataObject.Boolean(value));
return variable;
}
private static bool AttemptRangeSetMerge(Variable v, FunctionExpression rangeSetTerm, Expression toMergeWith, string logicalOpName)
{
if (toMergeWith is FunctionExpression) {
FunctionExpression functionExp = (FunctionExpression) toMergeWith;
// If the type is the same logical operation, we recurse
string funType = functionExp.Name;
if (funType.Equals(logicalOpName)) {
// Recurse condition, we try left and right merge
// We attempt left and right param
if (AttemptRangeSetMerge(v, rangeSetTerm, (Expression)functionExp.Parameters[0], logicalOpName))
return true;
return AttemptRangeSetMerge(v, rangeSetTerm, (Expression) functionExp.Parameters[1], logicalOpName);
}
// If it's a range set,
if (funType.Equals("range_set")) {
// Get the var
Variable targetVariable = ((FetchVariableExpression) functionExp.Parameters[0]).Variable;
// If they match, we merge
if (v.Equals(targetVariable)) {
// Get the range sets
SelectableRange rangeSet1 = (SelectableRange) functionExp.Parameters[1];
SelectableRange rangeSet2 = (SelectableRange) rangeSetTerm.Parameters[1];
// Make sure the range types are the same
SqlObject[] ob1 = (SqlObject[])toMergeWith.GetArgument("full_range_object");
SqlObject[] ob2 = (SqlObject[])rangeSetTerm.GetArgument("full_range_object");
if (ob1.Length != 1 || ob2.Length != 1)
// PENDING: Handle composite terms,
return false;
SqlType rs1Type = ob1[0].Type;
SqlType rs2Type = ob2[0].Type;
if (!rs1Type.Equals(rs2Type))
// Types are not strictly comparable, therefore can't merge,
return false;
// Merge (note that range_set1 which is part of 'to_merge_with'
// will be modified).
if (logicalOpName.Equals("@and_sql")) {
// intersect (and)
rangeSet1 = rangeSet1.Intersect(rangeSet2);
} else {
// union (or)
rangeSet1 = rangeSet1.Union(rangeSet2);
}
// Update the simplified term,
functionExp.Parameters[1] = rangeSet1;
return true;
}
// Not equal variables so return false
return false;
}
// fun_type isn't named "range_set", "or" or "and" so we return false
// indicating no merge is possible.
return false;
}
return false;
}
private void MarkUpIndexCandidates(Expression expression)
{
// If it's a fetch variable operation
if (expression is FetchVariableExpression) {
Variable var = ((FetchVariableExpression)expression).Variable;
// Get the table name
TableName tname = var.TableName;
// Get the TableDataSource for this table,
ITable tableSource = FetchTable(joinGraph, tname);
if (tableSource != null) {
// Get the list of indexes defined on this table,
TableName index_tname = tableSource.Name;
IIndexSetDataSource[] indexes = transaction.GetTableIndexes(index_tname);
foreach (IIndexSetDataSource ind in indexes) {
IndexCollation collation = ind.Collation;
// If the collation matches the var name then we have a match
if (collation.Columns.Length == 1 &&
collation.Columns[0].Equals(var.Name)) {
// Match found so mark it up
expression.IndexTableName = index_tname;
expression.IndexCandidate = ind.Name;
return;
}
}
}
}
// If it's a function,
else if (expression is FunctionExpression) {
FunctionExpression functionExp = (FunctionExpression) expression;
// If the exp is a range_set function then it's an index candidate,
String fuunctionName = functionExp.Name;
if (fuunctionName.Equals("range_set")) {
// Mark the fetch variable exp as an index candidate if we can
FetchVariableExpression fetch_var_op = (FetchVariableExpression)functionExp.Parameters[0];
MarkUpIndexCandidates(fetch_var_op);
}
// If its a simple comparison
else if (IsSimpleComparison(fuunctionName) ||
IsSimpleLogical(fuunctionName)) {
// Something like 'a = ?' is an index possibility
Expression p1 = (Expression) functionExp.Parameters[0];
Expression p2 = (Expression) functionExp.Parameters[1];
// Mark up them up if we can
MarkUpIndexCandidates(p1);
MarkUpIndexCandidates(p2);
}
// If it is a composite function
else if (fuunctionName.Equals("composite")) {
// A composite index
int paramCount = functionExp.Parameters.Count;
int termCount = paramCount / 2;
// If 1 term,
if (termCount == 1) {
// Recurse to the term,
MarkUpIndexCandidates((Expression) functionExp.Parameters[0]);
}
// Multiple terms,
else {
Variable[] vars = new Variable[termCount];
TableName tname = null;
bool valid = true;
for (int i = 0; i < termCount; ++i) {
// If the collation of the composite is descending, then we can't
// represent it as a composite index,
SqlObject tv = (SqlObject)functionExp.Parameters[(i * 2) + 1];
if (!tv.Value.ToBoolean()) {
valid = false;
break;
}
// Get the composite part operation
Expression compVar = (Expression)functionExp.Parameters[i * 2];
// Is it a var?
if (!(compVar is FetchVariableExpression)) {
valid = false;
break;
}
// Fetch the var,
Variable v = ((FetchVariableExpression)compVar).Variable;
// This var is in a different table,
if (i > 0 && !v.TableName.Equals(tname)) {
valid = false;
break;
}
// Ok, we know the composite part is a fetch var, and that the vars
// reference the same source, and it's ascending,
tname = v.TableName;
vars[i] = v;
}
// If the composite meets the indexable requirement look for an
// index,
if (valid) {
ITable tableSource = FetchTable(joinGraph, tname);
if (tableSource != null) {
// Get the list of indexes defined on this table,
TableName indexTableName = tableSource.Name;
IIndexSetDataSource[] indexes = transaction.GetTableIndexes(indexTableName);
foreach (IIndexSetDataSource ind in indexes) {
IndexCollation collation = ind.Collation;
// If the collation matches the number of terms,
if (collation.Columns.Length == termCount) {
bool matchFound = true;
for (int i = 0; i < termCount; ++i) {
if (!collation.Columns[i].Equals(vars[i].Name)) {
matchFound = false;
break;
}
}
// If match found, mark up the function,
if (matchFound) {
expression.IndexTableName = indexTableName;
expression.IndexCandidate = ind.Name;
return;
}
}
}
}
}
}
} else {
// index would not make sense so stop descending
return;
}
}
}
private static Variable Dereference(Expression graph, Variable v)
{
if (graph is FilterExpression)
// Recurse to the child
return Dereference(((FilterExpression)graph).Child, v);
if (graph is JoinExpression) {
JoinExpression joinExp = (JoinExpression) graph;
// Recurse the left and right nodes
Variable v2 = Dereference(joinExp.Left, v);
if (v2 == null || !v2.Equals(v))
return v2;
return Dereference(joinExp.Right, v);
}
if (graph is AliasTableNameExpression) {
AliasTableNameExpression aliasExp = (AliasTableNameExpression) graph;
if (aliasExp.Alias.Equals(v.TableName)) {
// Ok, match found, table name is in the child
Expression child = aliasExp.Child;
if (child is FetchTableExpression) {
TableName newTableName = ((FetchTableExpression)child).TableName;
return new Variable(newTableName, v.Name);
}
// Return null if the reference is to a nested query
return null;
}
return null;
}
if (graph is FunctionExpression)
return null;
throw new ApplicationException("Unknown operation type in graph.");
}
private Variable MakeStringVariable(string name, string value)
{
var variable = new Variable(new VariableInfo(name, PrimitiveTypes.String(), false));
variable.SetValue(DataObject.String(value));
return variable;
}
public Expression OnAfterWalk(Expression expression)
{
if (expression.Type == ExpressionType.Select) {
SelectExpression selectExp = (SelectExpression)expression;
// The current table name
TableName uniqueName = selectExp.UniqueName;
// Exiting a select, so first update the output vars
// The top remap stack for this select
Dictionary<Variable, Variable> curRemap = remapStack[remapStack.Count - 1];
remapStack.RemoveAt(remapStack.Count - 1);
List<Variable> outList = new List<Variable>();
int sz = selectExp.Output.Count;
for (int i = 0; i < sz; ++i) {
Expression outExp = selectExp.Output[i].Expression;
// What the output is currently called
Variable currentName = GetVariable(outExp);
// The new reference we are assigning it,
Variable newName = new Variable(uniqueName, "#C" + i);
// This is how we are mapping the output
outList.Add(currentName);
outList.Add(newName);
}
RemapAllVariables(selectExp, curRemap);
if (remapStack.Count > 0) {
if (selectExp.IsSourceSelect) {
for (int i = 0; i < sz; ++i) {
Expression outExp = selectExp.Output[i].Expression;
Variable curName = outList[i * 2];
Variable newName = outList[(i * 2) + 1];
if (outExp is AliasVariableNameExpression) {
((AliasVariableNameExpression) outExp).Alias = newName;
} else {
throw new ApplicationException("Unexpected operation.");
}
// Tell the parent map of these changes, if applicable,
Dictionary<Variable, Variable> parentRemap = remapStack[remapStack.Count - 1];
// Get any existing remap for this name
Variable existingMapTo = parentRemap[curName];
if (existingMapTo != null) {
// We just remap the name
parentRemap[curName] = new Variable(existingMapTo.TableName, newName.Name);
} else {
parentRemap[curName] = newName;
}
}
}
}
}
return expression;
}
public SelectOutput(Expression expression, Variable alias)
{
this.expression = expression;
this.alias = alias;
}
public Expression OnAfterWalk(Expression expression)
{
if (expression is SelectExpression) {
SelectExpression selectExp = (SelectExpression)expression;
// Exiting select, we expand the select output list to a complete
// form.
int sz = selectExp.Output.Count;
// Create a list of all forward referencable variables in the join
// graph
List<FetchVariableExpression> varList = new List<FetchVariableExpression>();
optimizer.PopulateVariables(varList, selectExp.Join);
// The unique table name of this select
TableName uniqueTableName = selectExp.UniqueName;
if (uniqueTableName == null)
throw new SystemException("Select must have a unique name.");
List<Expression> newOutList = new List<Expression>();
for (int i = 0; i < sz; ++i) {
// The Expression
SelectOutput selectOut = selectExp.Output[i];
// Is this a glob type?
if (selectOut.Expression is FetchGlobExpression) {
// Get the glob string
string str = ((FetchGlobExpression)selectOut.Expression).GlobString;
// Search the referencable list for matches,
bool matchFound = false;
foreach(FetchVariableExpression varExp in varList) {
Variable v = varExp.Variable;
// Found a match, add it to the list
if (optimizer.GlobMatch(str, v)) {
SqlType returnType = varExp.ReturnType;
Expression globExp = new FetchVariableExpression(v);
globExp = new AliasVariableNameExpression(globExp, v);
globExp.ReturnType = returnType;
newOutList.Add(globExp);
matchFound = true;
}
}
// If we searched the whole referencable list and no matches,
// we report the error. This doesn't apply to the general
// glob "*" which is valid for results with no columns.
if (!str.Equals("*") && !matchFound)
throw new SqlParseException("'" + str + "' does not match anything", selectOut.Expression);
} else {
// The makes sure all other types of output from a select are
// named variable references.
// If this is an alias, we need to make sure we qualify it with
// this table name
if (selectOut.Expression is AliasVariableNameExpression) {
// Rewrite this alias name with the new unique table id
Variable v = selectOut.Alias;
if (v.TableName != null)
throw new SqlParseException("Incorrect alias format", selectOut.Expression);
v = new Variable(uniqueTableName, v.Name);
selectOut.Alias = v;
}
// If it's not a fetchvar operation, we need to assign a
// unique alias name for this value
else if (!(selectOut.Expression is FetchVariableExpression)) {
string label = (string)selectOut.Expression.GetArgument("label");
if (label == null)
label = "nolabel";
selectOut = new SelectOutput(
new AliasVariableNameExpression(selectOut.Expression, new Variable(uniqueTableName, "#" + newOutList.Count + "#" + label)),
selectOut.Alias);
}
// If it's a regular fetch variable operation, we need to
// forward qualify it and label it.
else {
selectOut.Expression = QualifyExpression(selectOut.Expression, varList, true);
Variable var = ((FetchVariableExpression)selectOut.Expression).Variable;
SqlType returnType = selectOut.Expression.ReturnType;
selectOut.Expression = new AliasVariableNameExpression(selectOut.Expression, var);
selectOut.Expression.ReturnType = returnType;
}
// Add it to the new select output list
newOutList.Add(selectOut.Expression);
}
}
// new_out_list is now the new expanded select output list
sz = newOutList.Count;
selectExp.Output.Clear();
for (int i = 0; i < sz; ++i) {
selectExp.Output.Add(new SelectOutput(newOutList[i]));
}
// Set the qualified flag for each select statement,
selectExp.IsQualified = true;
}
return expression;
}
public Variable(Variable v)
{
table_name = v.table_name;
column_name = v.column_name;
}
private static IList<FetchVariableExpression> QualifyVariables(Variable v, IList<FetchVariableExpression> varList)
{
List<FetchVariableExpression> outList = new List<FetchVariableExpression>();
int sz = varList.Count;
for (int i = 0; i < sz; ++i) {
FetchVariableExpression varExp = varList[i];
Variable vin = varExp.Variable;
// Assume match unless shown otherwise
if (StringsMatch(v.Name, vin.Name)) {
TableName vtname = v.TableName;
TableName vintname = vin.TableName;
if (vtname == null ||
(StringsMatch(vtname.Name, vintname.Name) &&
StringsMatch(vtname.Schema, vintname.Schema))) {
outList.Add(varExp);
}
}
}
// Return the qualifying vars
return outList;
}
