fix the problem that expired data was not recycled timely due to slow…

… gc speed (#4224)

close #4146

dbms/src/Interpreters/Settings.h

@@ -258,8 +258,8 @@ struct Settings
  M(SettingUInt64, dt_segment_delta_small_column_file_size, 8388608, "Determine whether a column file in delta is small or not. 8MB by default.") \
  M(SettingUInt64, dt_segment_stable_pack_rows, DEFAULT_MERGE_BLOCK_SIZE, "Expected stable pack rows in DeltaTree Engine.") \
  M(SettingFloat, dt_segment_wait_duration_factor, 1, "The factor of wait duration in a write stall.") \
- M(SettingUInt64, dt_bg_gc_check_interval, 600, "Background gc thread check interval, the unit is second.") \
- M(SettingInt64, dt_bg_gc_max_segments_to_check_every_round, 15, "Max segments to check in every gc round, value less than or equal to 0 means gc no segments.") \
+ M(SettingUInt64, dt_bg_gc_check_interval, 5, "Background gc thread check interval, the unit is second.") \
+ M(SettingInt64, dt_bg_gc_max_segments_to_check_every_round, 100, "Max segments to check in every gc round, value less than or equal to 0 means gc no segments.") \
  M(SettingFloat, dt_bg_gc_ratio_threhold_to_trigger_gc, 1.2, "Trigger segment's gc when the ratio of invalid version exceed this threhold. Values smaller than or equal to 1.0 means gc all " \
  "segments") \
  M(SettingFloat, dt_bg_gc_delta_delete_ratio_to_trigger_gc, 0.3, "Trigger segment's gc when the ratio of delta delete range to stable exceeds this ratio.") \