[no-release-notes] edits for stat funcs (#2313)

* [no-release-notes] edits for stat funcs

* edit drop interface to switch on fisk flush

Author: max-hoffman

memory/stats.go

@@ -293,3 +293,12 @@ func (s *StatsProv) DataLength(ctx *sql.Context, db, table string) (uint64, erro
 	}
 	return size, nil
 }
+
+func (s *StatsProv) DropDbStats(ctx *sql.Context, db string, flush bool) error {
+	for key, _ := range s.colStats {
+		if strings.HasPrefix(string(key), db) {
+			delete(s.colStats, key)
+		}
+	}
+	return nil
+}

sql/analyzer/catalog.go

@@ -44,6 +44,10 @@ type Catalog struct {
 	locks sessionLocks
 }
 
+func (c *Catalog) DropDbStats(ctx *sql.Context, db string, flush bool) error {
+	return c.StatsProvider.DropDbStats(ctx, db, flush)
+}
+
 var _ sql.Catalog = (*Catalog)(nil)
 var _ sql.FunctionProvider = (*Catalog)(nil)
 var _ sql.TableFunctionProvider = (*Catalog)(nil)

sql/catalog_map.go

@@ -143,3 +143,8 @@ func (t MapCatalog) RowCount(ctx *Context, db, table string) (uint64, error) {
 func (t MapCatalog) DataLength(ctx *Context, db, table string) (uint64, error) {
 	return 1, nil
 }
+
+func (t MapCatalog) DropDbStats(ctx *Context, db string, flush bool) error {
+	//TODO implement me
+	panic("implement me")
+}

sql/statistics.go

@@ -43,6 +43,8 @@ type StatsProvider interface {
 	GetStats(ctx *Context, qual StatQualifier, cols []string) (Statistic, bool)
 	// DropStats deletes a set of column statistics
 	DropStats(ctx *Context, qual StatQualifier, cols []string) error
+	// DropAllStats deletes all database statistics
+	DropDbStats(ctx *Context, db string, flush bool) error
 	// RowCount returns the number of rows in a table
 	RowCount(ctx *Context, db, table string) (uint64, error)
 	// DataLength returns the estimated size of each row in the table

test/test_catalog.go

@@ -208,3 +208,8 @@ func (c *Catalog) DataLength(ctx *sql.Context, db, table string) (uint64, error)
 	//TODO implement me
 	panic("implement me")
 }
+
+func (c *Catalog) DropDbStats(ctx *sql.Context, db string, flush bool) error {
+	//TODO implement me
+	panic("implement me")
+}