3 ms·

Again that's great, its an ORM, that's what they do, try to abstract the DB from your language, and do their best to hide the impedance mismatch. However the m

Again that's great, its an ORM, that's what they do, try to abstract the DB from your language, and do their best to hide the impedance mismatch. However the mismatch is always there, the overhead of mapping types, inefficient serialization (key names repeated over and over in json vs a real schema), certain statements cannot be transpiled to sql so you have pathologic cases at unexpected times, in ability to run any statement you want in the db tier to take advantage of locality and so on. Most everyone wants a object database since most people are working with objects which is why ORM are so popular. Closet thing I ever saw was db4o.

philliphaydon 7y ago
It’s jsonb so you can’t repeat key names. Serialization is what ever you want to use for json serialization. Other than some report type queries I wanted to write I haven’t found anything that I couldn’t do in linq.
- SigmundA 7y ago
  jsonb doesn't do key interning as far as I know. Every field name will be repeated in every record vs a normal column which will only have the column name once in the db. This really adds up on a large database. Mongo used to recommend short key names and I even think some client would translate them based on some definition to try and save disk/memory/io https://github.com/postgrespro/zson https://github.com/postgrespro/zson tries to do key compression. Also its not that Linq can't do what you want, its that if you do certain things that can't be translated to SQL the whole intermediate result will be retrieved from the db, deserialized then the linq statement will be run in memory on the client. Its like putting ToList in the middle of your linq statement where a maybe a few million rows might need to be processed to give the very small result. If the linq statement was being run in process on the db server at least it would happen local to the data and would be more akin to a table scan vs index, still not great but much better then sending all the results to the client for processing.
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philliphaydon 7y ago

It’s jsonb so you can’t repeat key names. Serialization is what ever you want to use for json serialization. Other than some report type queries I wanted to write I haven’t found anything that I couldn’t do in linq.

SigmundA 7y ago
jsonb doesn't do key interning as far as I know. Every field name will be repeated in every record vs a normal column which will only have the column name once in the db. This really adds up on a large database. Mongo used to recommend short key names and I even think some client would translate them based on some definition to try and save disk/memory/io https://github.com/postgrespro/zson https://github.com/postgrespro/zson tries to do key compression. Also its not that Linq can't do what you want, its that if you do certain things that can't be translated to SQL the whole intermediate result will be retrieved from the db, deserialized then the linq statement will be run in memory on the client. Its like putting ToList in the middle of your linq statement where a maybe a few million rows might need to be processed to give the very small result. If the linq statement was being run in process on the db server at least it would happen local to the data and would be more akin to a table scan vs index, still not great but much better then sending all the results to the client for processing.

deleted 7y ago

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