Add EstimatedTableRowsCount to avoid count in large tables

This commit is contained in:
Allisson Azevedo
2018-06-14 16:10:59 -03:00
parent 2ce5e9a1e2
commit d603b293d8

View File

@@ -221,12 +221,35 @@ func (client *Client) TableRows(table string, opts RowsOptions) (*Result, error)
return client.query(sql)
}
func (client *Client) EstimatedTableRowsCount(table string, opts RowsOptions) (*Result, error) {
sql := fmt.Sprintf(`SELECT reltuples FROM pg_class WHERE relname = '%s'`, table)
result, err := client.query(sql)
if err != nil {
return nil, err
}
// float64 to int64 conversion
estimatedRowsCount := result.Rows[0][0].(float64)
result.Rows[0] = Row{int64(estimatedRowsCount)}
return result, nil
}
func (client *Client) TableRowsCount(table string, opts RowsOptions) (*Result, error) {
schema, table := getSchemaAndTable(table)
sql := fmt.Sprintf(`SELECT COUNT(1) FROM "%s"."%s"`, schema, table)
if opts.Where != "" {
sql += fmt.Sprintf(" WHERE %s", opts.Where)
} else {
tableInfo, err := client.TableInfo(table)
if err != nil {
return nil, err
}
estimatedRowsCount := tableInfo.Rows[0][3].(float64)
if estimatedRowsCount > 100000 {
return client.EstimatedTableRowsCount(table, opts)
}
}
return client.query(sql)