func (s *selectNode) ExplainTypes(regTypes func(string, string)) {
if s.filter != nil {
regTypes("filter", parser.AsStringWithFlags(s.filter, parser.FmtShowTypes))
}
for i, rexpr := range s.render {
regTypes(fmt.Sprintf("render %d", i), parser.AsStringWithFlags(rexpr, parser.FmtShowTypes))
}
}
func (n *limitNode) ExplainTypes(regTypes func(string, string)) {
if n.countExpr != nil {
regTypes("count", parser.AsStringWithFlags(n.countExpr, parser.FmtShowTypes))
}
if n.offsetExpr != nil {
regTypes("offset", parser.AsStringWithFlags(n.offsetExpr, parser.FmtShowTypes))
}
}
func (n *insertNode) ExplainTypes(regTypes func(string, string)) {
for i, dexpr := range n.defaultExprs {
regTypes(fmt.Sprintf("default %d", i), parser.AsStringWithFlags(dexpr, parser.FmtShowTypes))
}
for i, cexpr := range n.checkHelper.exprs {
regTypes(fmt.Sprintf("check %d", i), parser.AsStringWithFlags(cexpr, parser.FmtShowTypes))
}
cols := n.rh.columns
for i, rexpr := range n.rh.exprs {
regTypes(fmt.Sprintf("returning %s", cols[i].Name), parser.AsStringWithFlags(rexpr, parser.FmtShowTypes))
}
}
// explain extract information from planNodes and produces the EXPLAIN
// output via the makeRow callback in the explainer.
func (e *explainer) explain(plan planNode) {
if e.err != nil {
return
}
name, description, children := plan.ExplainPlan(e.showMetadata)
if name == "select" && !e.showSelectTop {
e.explain(children[len(children)-1])
return
}
e.node(name, description, plan)
if e.showExprs {
plan.explainExprs(func(elt string, expr parser.Expr) {
if e.err != nil {
return
}
if expr != nil {
e.attr(name, elt, parser.AsStringWithFlags(expr, e.fmtFlags))
}
})
}
for _, child := range children {
e.subnode(child)
}
}
// addOrMergeRenders adds the given result columns to the select
// render list and returns their column indices. If an expression is
// already rendered, and the reuse flag is true, no new render is
// added and the index of the existing column is returned instead.
func (s *selectNode) addOrMergeRenders(
cols ResultColumns, exprs []parser.TypedExpr, reuseExistingRender bool,
) (colIdxs []int) {
colIdxs = make([]int, len(cols))
for i := range cols {
index := -1
if reuseExistingRender {
// Now, try to find an equivalent render. We use the syntax
// representation as approximation of equivalence. At this
// point the expressions must have underwent name resolution
// already so that comparison occurs after replacing column names
// to IndexedVars.
exprStr := parser.AsStringWithFlags(exprs[i], parser.FmtSymbolicVars)
for j := range s.render {
if s.isRenderEquivalent(exprStr, j) {
index = j
break
}
}
}
if index == -1 {
index = len(s.render)
s.addRenderColumn(exprs[i], cols[i])
}
colIdxs[i] = index
}
return colIdxs
}
// expr implements the planObserver interface.
func (e *explainer) expr(nodeName, fieldName string, n int, expr parser.Expr) {
if e.showExprs && expr != nil {
if nodeName == "join" {
qualifySave := e.fmtFlags.ShowTableAliases
e.fmtFlags.ShowTableAliases = true
defer func() { e.fmtFlags.ShowTableAliases = qualifySave }()
}
if n >= 0 {
fieldName = fmt.Sprintf("%s %d", fieldName, n)
}
e.attr(nodeName, fieldName,
parser.AsStringWithFlags(expr, e.fmtFlags))
}
}
func (u *updateNode) ExplainTypes(regTypes func(string, string)) {
cols := u.rh.columns
for i, rexpr := range u.rh.exprs {
regTypes(fmt.Sprintf("returning %s", cols[i].Name), parser.AsStringWithFlags(rexpr, parser.FmtShowTypes))
}
}
// orderBy constructs a sortNode based on the ORDER BY clause.
//
// In the general case (SELECT/UNION/VALUES), we can sort by a column index or a
// column name.
//
// However, for a SELECT, we can also sort by the pre-alias column name (SELECT
// a AS b ORDER BY b) as well as expressions (SELECT a, b, ORDER BY a+b). In
// this case, construction of the sortNode might adjust the number of render
// targets in the selectNode if any ordering expressions are specified.
//
// TODO(dan): SQL also allows sorting a VALUES or UNION by an expression.
// Support this. It will reduce some of the special casing below, but requires a
// generalization of how to add derived columns to a SelectStatement.
func (p *planner) orderBy(orderBy parser.OrderBy, n planNode) (*sortNode, error) {
if orderBy == nil {
return nil, nil
}
// Multiple tests below use selectNode as a special case.
// So factor the cast.
s, _ := n.(*selectNode)
// We grab a copy of columns here because we might add new render targets
// below. This is the set of columns requested by the query.
columns := n.Columns()
numOriginalCols := len(columns)
if s != nil {
numOriginalCols = s.numOriginalCols
}
var ordering sqlbase.ColumnOrdering
for _, o := range orderBy {
direction := encoding.Ascending
if o.Direction == parser.Descending {
direction = encoding.Descending
}
index := -1
// Unwrap parenthesized expressions like "((a))" to "a".
expr := parser.StripParens(o.Expr)
// The logical data source for ORDER BY is the list of render
// expressions for a SELECT, as specified in the input SQL text
// (or an entire UNION or VALUES clause). Alas, SQL has some
// historical baggage and there are some special cases:
//
// 1) column ordinals. If a simple integer literal is used,
// optionally enclosed within parentheses but *not subject to
// any arithmetic*, then this refers to one of the columns of
// the data source. Then use the render expression at that
// ordinal position as sort key.
//
// 2) if the expression is the aliased (AS) name of a render
// expression in a SELECT clause, then use that
// render as sort key.
// e.g. SELECT a AS b, b AS c ORDER BY b
// this sorts on the first render.
//
// 3) otherwise, if the expression is already in the render list,
// then use that render as sort key.
// e.g. SELECT b AS c ORDER BY b
// this sorts on the first render.
// (this is an optimization)
//
// 4) if the sort key is not dependent on the data source (no
// IndexedVar) then simply do not sort. (this is an optimization)
//
// 5) otherwise, add a new render with the ORDER BY expression
// and use that as sort key.
// e.g. SELECT a FROM t ORDER by b
// e.g. SELECT a, b FROM t ORDER by a+b
//
// So first, deal with column ordinals.
col, err := p.colIndex(numOriginalCols, expr, "ORDER BY")
if err != nil {
return nil, err
}
if col != -1 {
index = col
}
// Now, deal with render aliases.
if vBase, ok := expr.(parser.VarName); index == -1 && ok {
v, err := vBase.NormalizeVarName()
if err != nil {
return nil, err
}
if c, ok := v.(*parser.ColumnItem); ok && c.TableName.Table() == "" {
// Look for an output column that matches the name. This
// handles cases like:
//
// SELECT a AS b FROM t ORDER BY b
target := c.ColumnName.Normalize()
for j, col := range columns {
if parser.ReNormalizeName(col.Name) == target {
index = j
break
}
}
}
}
if s != nil {
// Try to optimize constant sorts. For this we need to resolve
// names to IndexedVars then see if there were any vars
// substituted.
sortExpr := expr
if index != -1 {
// We found a render above, so fetch it. This is needed
// because if the sort expression is a reference to a render
// alias, resolveNames below would be incorrect.
sortExpr = s.render[index]
}
resolved, hasVars, err := p.resolveNames(sortExpr, s.sourceInfo, s.ivarHelper)
if err != nil {
return nil, err
}
if !hasVars {
// No sorting needed!
continue
}
// Now, try to find an equivalent render. We use the syntax
// representation as approximation of equivalence.
// We also use the expression after name resolution so
// that comparison occurs after replacing ordinal references
// to IndexedVars.
if index == -1 {
exprStr := parser.AsStringWithFlags(resolved, parser.FmtSymbolicVars)
for j, render := range s.render {
if parser.AsStringWithFlags(render, parser.FmtSymbolicVars) == exprStr {
index = j
break
}
}
}
}
// Finally, if we haven't found anything so far, we really
// need a new render.
// TODO(knz/dan) currently this is only possible for selectNode.
// If we are dealing with a UNION or something else we would need
// to fabricate an intermediate selectNode to add the new render.
if index == -1 && s != nil {
// We need to add a new render, but let's be careful: if there's
// a star in there, we're really adding multiple columns. These
// all become sort columns! And if no columns are expanded, then
// no columns become sort keys.
nextRenderIdx := len(s.render)
// TODO(knz) the optimizations above which reuse existing
// renders and skip ordering for constant expressions are not
// applied by addRender(). In other words, "ORDER BY foo.*" will
// not be optimized as well as "ORDER BY foo.x, foo.y". We
// could do this either here or as a separate later
// optimization.
if err := s.addRender(parser.SelectExpr{Expr: expr}, nil); err != nil {
return nil, err
}
for extraIdx := nextRenderIdx; extraIdx < len(s.render)-1; extraIdx++ {
// If more than 1 column were expanded, turn them into sort columns too.
// Except the last one, which will be added below.
ordering = append(ordering,
sqlbase.ColumnOrderInfo{ColIdx: extraIdx, Direction: direction})
}
if len(s.render) == nextRenderIdx {
// Nothing was expanded! So there is no order here.
continue
}
index = len(s.render) - 1
}
if index == -1 {
return nil, errors.Errorf("column %s does not exist", expr)
}
ordering = append(ordering,
sqlbase.ColumnOrderInfo{ColIdx: index, Direction: direction})
}
if ordering == nil {
// All the sort expressions are constant. Simply drop the sort node.
return nil, nil
}
return &sortNode{ctx: p.ctx(), p: p, columns: columns, ordering: ordering}, nil
}
// ExplainTypes implements the planNode interface.
func (n *joinNode) ExplainTypes(regTypes func(string, string)) {
if n.pred.filter != nil {
regTypes("filter", parser.AsStringWithFlags(n.pred.filter, parser.FmtShowTypes))
}
}
// TestCopyRandom inserts 100 random rows using COPY and ensures the SELECT'd
// data is the same.
func TestCopyRandom(t *testing.T) {
defer leaktest.AfterTest(t)()
params, _ := createTestServerParams()
s, db, _ := serverutils.StartServer(t, params)
defer s.Stopper().Stop()
if _, err := db.Exec(`
CREATE DATABASE d;
CREATE TABLE IF NOT EXISTS d.t (
id INT PRIMARY KEY,
n INTERVAL,
o BOOL,
i INT,
f FLOAT,
e DECIMAL,
t TIMESTAMP,
s STRING,
b BYTES,
tz TIMESTAMP WITH TIME ZONE
);
`); err != nil {
t.Fatal(err)
}
txn, err := db.Begin()
if err != nil {
t.Fatal(err)
}
stmt, err := txn.Prepare(pq.CopyInSchema("d", "t", "id", "n", "o", "i", "f", "e", "t", "s", "b", "tz"))
if err != nil {
t.Fatal(err)
}
rng := rand.New(rand.NewSource(0))
types := []sqlbase.ColumnType_Kind{
sqlbase.ColumnType_BOOL,
sqlbase.ColumnType_INT,
sqlbase.ColumnType_FLOAT,
sqlbase.ColumnType_DECIMAL,
sqlbase.ColumnType_TIMESTAMP,
sqlbase.ColumnType_STRING,
sqlbase.ColumnType_BYTES,
sqlbase.ColumnType_TIMESTAMPTZ,
}
var inputs [][]interface{}
for i := 0; i < 100; i++ {
row := make([]interface{}, len(types)+2)
row[0] = strconv.Itoa(i)
row[1] = time.Duration(rng.Int63()).String()
for j, t := range types {
d := sqlbase.RandDatum(rng, sqlbase.ColumnType{Kind: t}, false)
ds := parser.AsStringWithFlags(d, parser.FmtBareStrings)
switch t {
case sqlbase.ColumnType_DECIMAL:
// Trailing 0s aren't represented below, so truncate here.
ds = strings.TrimRight(ds, "0")
}
row[j+2] = ds
}
_, err = stmt.Exec(row...)
if err != nil {
t.Fatal(err)
}
inputs = append(inputs, row)
}
err = stmt.Close()
if err != nil {
t.Fatal(err)
}
err = txn.Commit()
if err != nil {
t.Fatal(err)
}
rows, err := db.Query("SELECT * FROM d.t ORDER BY id")
if err != nil {
t.Fatal(err)
}
for row, in := range inputs {
if !rows.Next() {
t.Fatal("expected more results")
}
data := make([]interface{}, len(in))
for i := range data {
data[i] = new(interface{})
}
if err := rows.Scan(data...); err != nil {
t.Fatal(err)
}
for i, d := range data {
v := d.(*interface{})
d := *v
ds := fmt.Sprint(d)
switch d := d.(type) {
case []byte:
ds = string(d)
case time.Time:
dt := parser.MakeDTimestamp(d, time.Microsecond)
ds = parser.AsStringWithFlags(dt, parser.FmtBareStrings)
}
if !reflect.DeepEqual(in[i], ds) {
t.Fatalf("row %v, col %v: got %#v (%T), expected %#v", row, i, ds, d, in[i])
}
}
}
}
// isRenderEquivalent is a helper function for equivalentRenders() and
// addOrMergeRenders(). Do not use directly.
func (s *selectNode) isRenderEquivalent(exprStr string, j int) bool {
return parser.AsStringWithFlags(s.render[j], parser.FmtSymbolicVars) == exprStr
}
// equivalentRenders returns true if and only if the two render expressions
// are equivalent.
func (s *selectNode) equivalentRenders(i, j int) bool {
firstExprStr := parser.AsStringWithFlags(s.render[i], parser.FmtSymbolicVars)
return s.isRenderEquivalent(firstExprStr, j)
}
