update default batch & add batch check for update mode

[Nicole00]

No description provided.

[codecov-commenter]

Codecov Report

Merging #27 (a341ded) into master (fe32819) will decrease coverage by 0.06%.
The diff coverage is 66.66%.

@@             Coverage Diff              @@
##             master      #27      +/-   ##
============================================
- Coverage     74.02%   73.96%   -0.07%     
  Complexity      152      152              
============================================
  Files            24       24              
  Lines          1567     1571       +4     
  Branches        247      251       +4     
============================================
+ Hits           1160     1162       +2     
  Misses          264      264              
- Partials        143      145       +2     

Impacted Files	Coverage Δ
...ala/com/vesoft/nebula/connector/NebulaConfig.scala	78.80% <66.66%> (-0.35%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update fe32819...a341ded. Read the comment docs.