// filters walks the where clause of a select statement and returns a map with all series ids // matching the where clause and any filter expression that should be applied to each func (m *Measurement) filters(condition influxql.Expr) (map[uint64]influxql.Expr, error) { if condition == nil || influxql.OnlyTimeExpr(condition) { seriesIdsToExpr := make(map[uint64]influxql.Expr, len(m.seriesIDs)) for _, id := range m.seriesIDs { seriesIdsToExpr[id] = nil } return seriesIdsToExpr, nil } ids, seriesIdsToExpr, err := m.walkWhereForSeriesIds(condition) if err != nil { return nil, err } // Ensure every id is in the map and replace literal true expressions with // nil so the engine doesn't waste time evaluating them. for _, id := range ids { if expr, ok := seriesIdsToExpr[id]; !ok { seriesIdsToExpr[id] = nil } else if b, ok := expr.(*influxql.BooleanLiteral); ok && b.Val { seriesIdsToExpr[id] = nil } } return seriesIdsToExpr, nil }
// Ensure that we see if a where clause has only time limitations func TestOnlyTimeExpr(t *testing.T) { var tests = []struct { stmt string exp bool }{ { stmt: `SELECT value FROM myseries WHERE value > 1`, exp: false, }, { stmt: `SELECT value FROM foo WHERE time >= '2000-01-01T00:00:05Z'`, exp: true, }, { stmt: `SELECT value FROM foo WHERE time >= '2000-01-01T00:00:05Z' AND time < '2000-01-01T00:00:05Z'`, exp: true, }, { stmt: `SELECT value FROM foo WHERE time >= '2000-01-01T00:00:05Z' AND asdf = 'bar'`, exp: false, }, { stmt: `SELECT value FROM foo WHERE asdf = 'jkl' AND (time >= '2000-01-01T00:00:05Z' AND time < '2000-01-01T00:00:05Z')`, exp: false, }, } for i, tt := range tests { // Parse statement. stmt, err := influxql.NewParser(strings.NewReader(tt.stmt)).ParseStatement() if err != nil { t.Fatalf("invalid statement: %q: %s", tt.stmt, err) } if influxql.OnlyTimeExpr(stmt.(*influxql.SelectStatement).Condition) != tt.exp { t.Fatalf("%d. expected statement to return only time dimension to be %t: %s", i, tt.exp, tt.stmt) } } }