Add hash-based indexes

This commit is contained in:
Barak Michener 2015-08-07 14:35:24 -04:00
parent c98318aa97
commit ab3f59d21f
5 changed files with 95 additions and 44 deletions

View file

@ -1,8 +1,12 @@
package sql package sql
import ( import (
"crypto/sha1"
"database/sql" "database/sql"
"encoding/hex"
"fmt" "fmt"
"hash"
"sync"
"github.com/lib/pq" "github.com/lib/pq"
@ -18,6 +22,13 @@ func init() {
graph.RegisterQuadStore(QuadStoreType, true, newQuadStore, createSQLTables, nil) graph.RegisterQuadStore(QuadStoreType, true, newQuadStore, createSQLTables, nil)
} }
var (
hashPool = sync.Pool{
New: func() interface{} { return sha1.New() },
}
hashSize = sha1.Size
)
type QuadStore struct { type QuadStore struct {
db *sql.DB db *sql.DB
sqlFlavor string sqlFlavor string
@ -55,7 +66,11 @@ func createSQLTables(addr string, options graph.Options) error {
horizon BIGSERIAL PRIMARY KEY, horizon BIGSERIAL PRIMARY KEY,
id BIGINT, id BIGINT,
ts timestamp, ts timestamp,
UNIQUE(subject, predicate, object, label) subject_hash TEXT NOT NULL,
predicate_hash TEXT NOT NULL,
object_hash TEXT NOT NULL,
label_hash TEXT,
UNIQUE(subject_hash, predicate_hash, object_hash, label_hash)
);`) );`)
if err != nil { if err != nil {
glog.Errorf("Cannot create quad table: %v", quadTable) glog.Errorf("Cannot create quad table: %v", quadTable)
@ -73,17 +88,11 @@ func createSQLTables(addr string, options graph.Options) error {
CREATE INDEX pos_index ON quads USING brin(predicate) WITH (pages_per_range = 32); CREATE INDEX pos_index ON quads USING brin(predicate) WITH (pages_per_range = 32);
CREATE INDEX osp_index ON quads USING brin(object) WITH (pages_per_range = 32); CREATE INDEX osp_index ON quads USING brin(object) WITH (pages_per_range = 32);
`) `)
} else if idxStrat == "prefix" {
index, err = tx.Exec(fmt.Sprintf(`
CREATE INDEX spo_index ON quads (substr(subject, 0, 8)) WITH (FILLFACTOR = %d);
CREATE INDEX pos_index ON quads (substr(predicate, 0, 8)) WITH (FILLFACTOR = %d);
CREATE INDEX osp_index ON quads (substr(object, 0, 8)) WITH (FILLFACTOR = %d);
`, factor, factor, factor))
} else { } else {
index, err = tx.Exec(fmt.Sprintf(` index, err = tx.Exec(fmt.Sprintf(`
CREATE INDEX spo_index ON quads (subject, predicate, object) WITH (FILLFACTOR = %d); CREATE INDEX spo_index ON quads (subject_hash) WITH (FILLFACTOR = %d);
CREATE INDEX pos_index ON quads (predicate, object, subject) WITH (FILLFACTOR = %d); CREATE INDEX pos_index ON quads (predicate_hash) WITH (FILLFACTOR = %d);
CREATE INDEX osp_index ON quads (object, subject, predicate) WITH (FILLFACTOR = %d); CREATE INDEX osp_index ON quads (object_hash) WITH (FILLFACTOR = %d);
`, factor, factor, factor)) `, factor, factor, factor))
} }
if err != nil { if err != nil {
@ -107,13 +116,34 @@ func newQuadStore(addr string, options graph.Options) (graph.QuadStore, error) {
return &qs, nil return &qs, nil
} }
func hashOf(s string) string {
h := hashPool.Get().(hash.Hash)
h.Reset()
defer hashPool.Put(h)
key := make([]byte, 0, hashSize)
h.Write([]byte(s))
key = h.Sum(key)
return hex.EncodeToString(key)
}
func (qs *QuadStore) copyFrom(tx *sql.Tx, in []graph.Delta) error { func (qs *QuadStore) copyFrom(tx *sql.Tx, in []graph.Delta) error {
stmt, err := tx.Prepare(pq.CopyIn("quads", "subject", "predicate", "object", "label", "id", "ts")) stmt, err := tx.Prepare(pq.CopyIn("quads", "subject", "predicate", "object", "label", "id", "ts", "subject_hash", "predicate_hash", "object_hash", "label_hash"))
if err != nil { if err != nil {
return err return err
} }
for _, d := range in { for _, d := range in {
_, err := stmt.Exec(d.Quad.Subject, d.Quad.Predicate, d.Quad.Object, d.Quad.Label, d.ID.Int(), d.Timestamp) _, err := stmt.Exec(
d.Quad.Subject,
d.Quad.Predicate,
d.Quad.Object,
d.Quad.Label,
d.ID.Int(),
d.Timestamp,
hashOf(d.Quad.Subject),
hashOf(d.Quad.Predicate),
hashOf(d.Quad.Object),
hashOf(d.Quad.Label),
)
if err != nil { if err != nil {
glog.Errorf("couldn't prepare COPY statement: %v", err) glog.Errorf("couldn't prepare COPY statement: %v", err)
return err return err
@ -137,7 +167,7 @@ func (qs *QuadStore) buildTxPostgres(tx *sql.Tx, in []graph.Delta) error {
return qs.copyFrom(tx, in) return qs.copyFrom(tx, in)
} }
insert, err := tx.Prepare(`INSERT INTO quads(subject, predicate, object, label, id, ts) VALUES ($1, $2, $3, $4, $5, $6)`) insert, err := tx.Prepare(`INSERT INTO quads(subject, predicate, object, label, id, ts, subject_hash, predicate_hash, object_hash, label_hash) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)`)
if err != nil { if err != nil {
glog.Errorf("Cannot prepare insert statement: %v", err) glog.Errorf("Cannot prepare insert statement: %v", err)
return err return err
@ -145,7 +175,18 @@ func (qs *QuadStore) buildTxPostgres(tx *sql.Tx, in []graph.Delta) error {
for _, d := range in { for _, d := range in {
switch d.Action { switch d.Action {
case graph.Add: case graph.Add:
_, err := insert.Exec(d.Quad.Subject, d.Quad.Predicate, d.Quad.Object, d.Quad.Label, d.ID.Int(), d.Timestamp) _, err := insert.Exec(
d.Quad.Subject,
d.Quad.Predicate,
d.Quad.Object,
d.Quad.Label,
d.ID.Int(),
d.Timestamp,
hashOf(d.Quad.Subject),
hashOf(d.Quad.Predicate),
hashOf(d.Quad.Object),
hashOf(d.Quad.Label),
)
if err != nil { if err != nil {
glog.Errorf("couldn't prepare INSERT statement: %v", err) glog.Errorf("couldn't prepare INSERT statement: %v", err)
return err return err
@ -271,7 +312,7 @@ func (qs *QuadStore) sizeForIterator(isAll bool, dir quad.Direction, val string)
var size int64 var size int64
glog.V(4).Infoln("sql: getting size for select %s, %s", dir.String(), val) glog.V(4).Infoln("sql: getting size for select %s, %s", dir.String(), val)
err = qs.db.QueryRow( err = qs.db.QueryRow(
fmt.Sprintf("SELECT count(*) FROM quads WHERE %s = $1;", dir.String()), val).Scan(&size) fmt.Sprintf("SELECT count(*) FROM quads WHERE %s_hash = $1;", dir.String()), hashOf(val)).Scan(&size)
if err != nil { if err != nil {
glog.Errorln("Error getting size from SQL database: %v", err) glog.Errorln("Error getting size from SQL database: %v", err)
return 0 return 0

View file

@ -290,7 +290,7 @@ func (it *SQLIterator) makeCursor(next bool, value graph.Value) error {
} }
var q string var q string
var values []string var values []string
q, values = it.sql.buildSQL(next, value) q, values = it.sql.buildSQL(next, value, false)
q = convertToPostgres(q, values) q = convertToPostgres(q, values)
ivalues := make([]interface{}, 0, len(values)) ivalues := make([]interface{}, 0, len(values))
for _, v := range values { for _, v := range values {

View file

@ -50,11 +50,11 @@ type tagDir struct {
func (t tagDir) String() string { func (t tagDir) String() string {
if t.dir == quad.Any { if t.dir == quad.Any {
if t.justLocal { if t.justLocal {
return fmt.Sprintf("%s.__execd as %s", t.table, t.tag) return fmt.Sprintf("%s.__execd as %s, %s.__execd_hash as %s_hash", t.table, t.tag, t.table, t.tag)
} }
return fmt.Sprintf("%s.%s as %s", t.table, t.tag, t.tag) return fmt.Sprintf("%s.%s as %s, %s.%s_hash as %s_hash", t.table, t.tag, t.tag, t.table, t.tag, t.tag)
} }
return fmt.Sprintf("%s.%s as %s", t.table, t.dir, t.tag) return fmt.Sprintf("%s.%s as %s, %s.%s_hash as %s_hash", t.table, t.dir, t.tag, t.table, t.dir, t.tag)
} }
type tableDef struct { type tableDef struct {
@ -71,7 +71,7 @@ type sqlItDir struct {
type sqlIterator interface { type sqlIterator interface {
sqlClone() sqlIterator sqlClone() sqlIterator
buildSQL(next bool, val graph.Value) (string, []string) buildSQL(next bool, val graph.Value, hash bool) (string, []string)
getTables() []tableDef getTables() []tableDef
getTags() []tagDir getTags() []tagDir
buildWhere() (string, []string) buildWhere() (string, []string)
@ -219,8 +219,8 @@ func (l *SQLLinkIterator) buildWhere() (string, []string) {
var q []string var q []string
var vals []string var vals []string
for _, c := range l.constraints { for _, c := range l.constraints {
q = append(q, fmt.Sprintf("%s.%s = ?", l.tableName, c.dir)) q = append(q, fmt.Sprintf("%s.%s_hash = ?", l.tableName, c.dir))
vals = append(vals, c.vals[0]) vals = append(vals, hashOf(c.vals[0]))
} }
for _, i := range l.nodeIts { for _, i := range l.nodeIts {
t := i.it.tableID() t := i.it.tableID()
@ -228,7 +228,7 @@ func (l *SQLLinkIterator) buildWhere() (string, []string) {
if t.dir == quad.Any { if t.dir == quad.Any {
dir = t.tag dir = t.tag
} }
q = append(q, fmt.Sprintf("%s.%s = %s.%s", l.tableName, i.dir, t.table, dir)) q = append(q, fmt.Sprintf("%s.%s_hash = %s.%s_hash", l.tableName, i.dir, t.table, dir))
} }
for _, i := range l.nodeIts { for _, i := range l.nodeIts {
s, v := i.it.buildWhere() s, v := i.it.buildWhere()
@ -246,13 +246,17 @@ func (l *SQLLinkIterator) tableID() tagDir {
} }
} }
func (l *SQLLinkIterator) buildSQL(next bool, val graph.Value) (string, []string) { func (l *SQLLinkIterator) buildSQL(next bool, val graph.Value, hash bool) (string, []string) {
query := "SELECT DISTINCT " query := "SELECT DISTINCT "
hashs := ""
if hash {
hashs = "_hash"
}
t := []string{ t := []string{
fmt.Sprintf("%s.subject", l.tableName), fmt.Sprintf("%s.subject%s", l.tableName, hashs),
fmt.Sprintf("%s.predicate", l.tableName), fmt.Sprintf("%s.predicate%s", l.tableName, hashs),
fmt.Sprintf("%s.object", l.tableName), fmt.Sprintf("%s.object%s", l.tableName, hashs),
fmt.Sprintf("%s.label", l.tableName), fmt.Sprintf("%s.label%s", l.tableName, hashs),
} }
for _, v := range l.getTags() { for _, v := range l.getTags() {
t = append(t, v.String()) t = append(t, v.String())
@ -276,16 +280,16 @@ func (l *SQLLinkIterator) buildSQL(next bool, val graph.Value) (string, []string
constraint += " AND " constraint += " AND "
} }
t = []string{ t = []string{
fmt.Sprintf("%s.subject = ?", l.tableName), fmt.Sprintf("%s.subject_hash = ?", l.tableName),
fmt.Sprintf("%s.predicate = ?", l.tableName), fmt.Sprintf("%s.predicate_hash = ?", l.tableName),
fmt.Sprintf("%s.object = ?", l.tableName), fmt.Sprintf("%s.object_hash = ?", l.tableName),
fmt.Sprintf("%s.label = ?", l.tableName), fmt.Sprintf("%s.label_hash = ?", l.tableName),
} }
constraint += strings.Join(t, " AND ") constraint += strings.Join(t, " AND ")
values = append(values, v.Subject) values = append(values, hashOf(v.Subject))
values = append(values, v.Predicate) values = append(values, hashOf(v.Predicate))
values = append(values, v.Object) values = append(values, hashOf(v.Object))
values = append(values, v.Label) values = append(values, hashOf(v.Label))
} }
query += constraint query += constraint
query += ";" query += ";"

View file

@ -69,6 +69,9 @@ func (n *SQLNodeIntersection) Describe() string {
func (n *SQLNodeIntersection) buildResult(result []string, cols []string) map[string]string { func (n *SQLNodeIntersection) buildResult(result []string, cols []string) map[string]string {
m := make(map[string]string) m := make(map[string]string)
for i, c := range cols { for i, c := range cols {
if strings.HasSuffix(c, "_hash") {
continue
}
if c == "__execd" { if c == "__execd" {
n.result = result[i] n.result = result[i]
} }
@ -100,7 +103,7 @@ func (n *SQLNodeIntersection) buildSubqueries() []tableDef {
for i, it := range n.nodeIts { for i, it := range n.nodeIts {
var td tableDef var td tableDef
var table string var table string
table, td.values = it.buildSQL(true, nil) table, td.values = it.buildSQL(true, nil, true)
td.table = fmt.Sprintf("\n(%s)", table[:len(table)-1]) td.table = fmt.Sprintf("\n(%s)", table[:len(table)-1])
td.name = n.nodetables[i] td.name = n.nodetables[i]
out = append(out, td) out = append(out, td)
@ -150,13 +153,13 @@ func (n *SQLNodeIntersection) buildWhere() (string, []string) {
var q []string var q []string
var vals []string var vals []string
for _, tb := range n.nodetables[1:] { for _, tb := range n.nodetables[1:] {
q = append(q, fmt.Sprintf("%s.__execd = %s.__execd", n.nodetables[0], tb)) q = append(q, fmt.Sprintf("%s.__execd_hash = %s.__execd_hash", n.nodetables[0], tb))
} }
query := strings.Join(q, " AND ") query := strings.Join(q, " AND ")
return query, vals return query, vals
} }
func (n *SQLNodeIntersection) buildSQL(next bool, val graph.Value) (string, []string) { func (n *SQLNodeIntersection) buildSQL(next bool, val graph.Value, _ bool) (string, []string) {
topData := n.tableID() topData := n.tableID()
tags := []tagDir{topData} tags := []tagDir{topData}
tags = append(tags, n.getTags()...) tags = append(tags, n.getTags()...)
@ -184,8 +187,8 @@ func (n *SQLNodeIntersection) buildSQL(next bool, val graph.Value) (string, []st
if constraint != "" { if constraint != "" {
constraint += " AND " constraint += " AND "
} }
constraint += fmt.Sprintf("%s.%s = ?", topData.table, topData.dir) constraint += fmt.Sprintf("%s.%s_hash = ?", topData.table, topData.dir)
values = append(values, v) values = append(values, hashOf(v))
} }
query += constraint query += constraint
query += ";" query += ";"

View file

@ -89,6 +89,9 @@ func (n *SQLNodeIterator) Describe() string {
func (n *SQLNodeIterator) buildResult(result []string, cols []string) map[string]string { func (n *SQLNodeIterator) buildResult(result []string, cols []string) map[string]string {
m := make(map[string]string) m := make(map[string]string)
for i, c := range cols { for i, c := range cols {
if strings.HasSuffix(c, "_hash") {
continue
}
if c == "__execd" { if c == "__execd" {
n.result = result[i] n.result = result[i]
} }
@ -157,7 +160,7 @@ func (n *SQLNodeIterator) buildWhere() (string, []string) {
return query, vals return query, vals
} }
func (n *SQLNodeIterator) buildSQL(next bool, val graph.Value) (string, []string) { func (n *SQLNodeIterator) buildSQL(next bool, val graph.Value, _ bool) (string, []string) {
topData := n.tableID() topData := n.tableID()
tags := []tagDir{topData} tags := []tagDir{topData}
tags = append(tags, n.getTags()...) tags = append(tags, n.getTags()...)
@ -185,8 +188,8 @@ func (n *SQLNodeIterator) buildSQL(next bool, val graph.Value) (string, []string
if constraint != "" { if constraint != "" {
constraint += " AND " constraint += " AND "
} }
constraint += fmt.Sprintf("%s.%s = ?", topData.table, topData.dir) constraint += fmt.Sprintf("%s.%s_hash = ?", topData.table, topData.dir)
values = append(values, v) values = append(values, hashOf(v))
} }
query += constraint query += constraint
query += ";" query += ";"