# Best practice on getting data out of RDBMS(PostgreSQL)? **URL:** \ **Category:** Elasticsearch\ **Created:** [June 6, 2013, 7:40pm UTC](https://discuss.elastic.co/t/best-practice-on-getting-data-out-of-rdbms-postgresql/12306 "2013-06-06T19:40:08Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![AlexeyV](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alexeyv/32/2126_2.png) [@AlexeyV](https://discuss.elastic.co/u/AlexeyV)\ **Post date:** [June 6, 2013, 7:40pm UTC](https://discuss.elastic.co/t/best-practice-on-getting-data-out-of-rdbms-postgresql/12306/1 "2013-06-06T19:40:08Z")
Hi, i've looked into setting up jdbc river from postgres but running into issues where only onetime snapshots are working. Just curious how is everyone else pushing data to ES and handling changes? I was going to dig more into jdbc river and see if i can get deltas working, currently there are few bugs/issues with it. Another thought was to use index aliases, building new index and altering alias by adding/removing new/old index but i havent figured out fully automation process around that. Any feedback is much appreciated. -Alexey -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![jprante](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jprante/32/44941_2.png) [@jprante](https://discuss.elastic.co/u/jprante)\ **Post date:** [June 7, 2013, 8:08am UTC](https://discuss.elastic.co/t/best-practice-on-getting-data-out-of-rdbms-postgresql/12306/2 "2013-06-07T08:08:16Z")
For the JDBC river, I started to implement only a demonstration of how data can be read from tabular data model in RDBMS and moved into the JSON doc model, without providing the configuration of all the data domains that are possible. If you can provide a single SQL statement for fetching the data, you get it. Automating the creation of deltas on relational data depends on the domain of the relational model, which is difficult. Not always a match with the JSON document model is guarantueed, or with the ES index/type/docid style of addressing. So the first challenge to move updates from tabular data to ES is identifying the updates and assign ES doc IDs to it, or other ES features, like parent/child. Also, because ES overwriting of docs with same IDs is simple, you have to take care of your style of bulk index versions. Versions may be accomplished by ES versions (like I tried) or by different ES indexes, maybe daily versions, and automatic clean up of old versions. By following this strategy, it is straightforward to move all of the data you have. It does not make much sense to fiddle with single fields and update them in existing ES documents, because, if you have many updates, the overhead becomes significant soon and does not scale well in search engines with inverted indexes like ES. Switching to a fresh index is faster and ES supports this cool feature. Jörg Am 06.06.2013 21:40, schrieb Alexey Volochenko: > Hi, i've looked into setting up jdbc river from postgres but running > into issues where only onetime snapshots are working. Just curious how > is everyone else pushing data to ES and handling changes? > I was going to dig more into jdbc river and see if i can get deltas > working, currently there are few bugs/issues with it. Another thought > was to use index aliases, building new index and altering alias by > adding/removing new/old index but i havent figured out fully > automation process around that. Any feedback is much appreciated. > > ## -Alexey > > You received this message because you are subscribed to the Google > Groups "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send > an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 2:32am UTC](https://discuss.elastic.co/t/best-practice-on-getting-data-out-of-rdbms-postgresql/12306/3 "2017-07-06T02:32:25Z")