mongodb - Mongo db Indexing -


i using mongodb database ongoing project since last 3 months. when starting mongodb, didn’t have clear idea indexing. curranty not have @ least 1 indexing in whole database. abnormally slow when querying data 2 thousand documents. hope make table indexes robo 3t mongo database management tool , got 2 questions.

  1. if create indexes on current database, create indexes available data? or effects new records only?
  2. in queries using more 1 fields of specific collection $match filter out data , using 1 fields of same collection. question creating compound indexes , single indexes match both cases best practice or not?


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