what is the best way to sync data with elastic search from SQL server

PGSync is one way to sync data from Postgres to ES

You can use logstash to pull in data from a jdbc connection. https://www.elastic.co/guide/en/logstash/current/plugins-inputs-jdbc.html Alternatively you can fairly easily write a sync job that fires periodically that pushes data into your sql db using the elasticsearch api. Depending on how you are hosting your sql server there maybe other options you can take advantage of. For example if you are using AWS you can use tools like Lambda and Kineses to run sync jobs that automatically scale and deal with high volume.

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