Optimize span query based on maximum time duration

Using the max time duration of a trace, we can optimize the query by
searching chunks only within the window of possibilites when we know
the time for one of the traces of the span.

We optimize the span, link, and event hypertable scans.

On some tests, decreased query time from 3s to 300ms.

pkg/jaeger/query/query.go

@@ -21,12 +21,11 @@ import (
 
 type Query struct {
 	conn    pgxconn.PgxConn
-	cfg     *Config
 	builder *Builder
 }
 
 func New(conn pgxconn.PgxConn, cfg *Config) *Query {
-	return &Query{conn, cfg, NewBuilder(cfg)}
+	return &Query{conn, NewBuilder(cfg)}
 }
 
 func (p *Query) SpanReader() spanstore.Reader {

pkg/jaeger/query/trace_query.go

@@ -52,15 +52,15 @@ const (
 	LEFT JOIN
 		_ps_trace.schema_url s_url ON s.resource_schema_url_id = s_url.id
 	LEFT JOIN
-		_ps_trace.event e ON e.span_id = s.span_id AND e.trace_id = s.trace_id
+		_ps_trace.event e ON e.span_id = s.span_id AND e.trace_id = s.trace_id %[3]s
 	LEFT JOIN
 		_ps_trace.instrumentation_lib inst_lib ON s.instrumentation_lib_id = inst_lib.id
 	LEFT JOIN
 		_ps_trace.schema_url inst_lib_url ON inst_lib_url.id = inst_lib.schema_url_id
 	LEFT JOIN
-		_ps_trace.link lk ON lk.trace_id = s.trace_id AND lk.span_id = s.span_id
+		_ps_trace.link lk ON lk.trace_id = s.trace_id AND lk.span_id = s.span_id %[4]s
 	WHERE
-	  %s
+	  %[1]s %[2]s
 	GROUP BY
 	  s.trace_id,
 	  s.span_id,
@@ -78,14 +78,14 @@ const (
 
 	subqueryFormat = `
 	SELECT
-		trace_sub.trace_id
+		trace_sub.trace_id, start_time_max - $%[1]d::interval as time_low, start_time_max + $%[1]d::interval as time_high
 	FROM (
 		SELECT
 			trace_id,
 			max(start_time) as start_time_max
 		FROM _ps_trace.span s
 		WHERE
-			%s
+			%[2]s
 		GROUP BY trace_id
 	) as trace_sub
 	ORDER BY trace_sub.start_time_max DESC
@@ -116,16 +116,34 @@ func NewBuilder(cfg *Config) *Builder {
 	return &Builder{cfg}
 }
 
-func (b *Builder) buildCompleteTraceQuery(traceIDClause string) string {
+func (b *Builder) buildCompleteTraceQuery(traceIDClause string, timeLowRef string, timeHighRef string) string {
+	spanTimeClause := ""
+	eventTimeClause := ""
+	linkTimeClause := ""
+	if timeLowRef != "" {
+		spanTimeClause += " AND s.start_time > " + timeLowRef
+		eventTimeClause += " AND e.time > " + timeLowRef
+		linkTimeClause += " AND lk.span_start_time > " + timeLowRef
+	}
+	if timeHighRef != "" {
+		spanTimeClause += " AND s.start_time < " + timeHighRef
+		eventTimeClause += " AND e.time < " + timeHighRef
+		linkTimeClause += " AND lk.span_start_time < " + timeHighRef
+	}
+
 	return fmt.Sprintf(
 		completeTraceSQLFormat,
-		traceIDClause)
+		traceIDClause,
+		spanTimeClause,
+		eventTimeClause,
+		linkTimeClause,
+	)
 }
 
 func (b *Builder) findTracesQuery(q *spanstore.TraceQueryParameters) (string, []interface{}) {
 	subquery, params := b.buildTraceIDSubquery(q)
 	traceIDClause := "s.trace_id = trace_ids.trace_id"
-	completeTraceSQL := b.buildCompleteTraceQuery(traceIDClause)
+	completeTraceSQL := b.buildCompleteTraceQuery(traceIDClause, "trace_ids.time_low", "trace_ids.time_high")
 	return fmt.Sprintf(findTraceSQLFormat, subquery, completeTraceSQL), params
 }
 
@@ -148,7 +166,7 @@ func (b *Builder) getTraceQuery(traceID model.TraceID) (string, []interface{}, e
 	params := []interface{}{uuid}
 
 	traceIDClause := "s.trace_id = $1"
-	return b.buildCompleteTraceQuery(traceIDClause), params, nil
+	return b.buildCompleteTraceQuery(traceIDClause, "", ""), params, nil
 }
 
 func (b *Builder) buildTraceIDSubquery(q *spanstore.TraceQueryParameters) (string, []interface{}) {
@@ -228,12 +246,16 @@ func (b *Builder) buildTraceIDSubquery(q *spanstore.TraceQueryParameters) (strin
 
 	}
 
-	query := ""
+	clauseString := ""
 	if len(clauses) > 0 {
-		query = fmt.Sprintf(subqueryFormat, strings.Join(clauses, " AND "))
+		clauseString = strings.Join(clauses, " AND ")
 	} else {
-		query = fmt.Sprintf(subqueryFormat, "TRUE")
+		clauseString = "TRUE"
 	}
+	params = append(params, b.cfg.MaxTraceDuration)
+	//Note: the parameter number for b.cfg.MaxTraceDuration is used in two places ($%[1]d in subqueryFormat)
+	//to both add and subtract from start_time_max.
+	query := fmt.Sprintf(subqueryFormat, len(params), clauseString)
 
 	if q.NumTraces != 0 {
 		query += fmt.Sprintf(" LIMIT %d", q.NumTraces)