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My first JSON DB project did not go well because the data structure (or lack thereof) quickly overwhelmed the applications ability to process it. If I had it to do over again I would have put more of the application in the database to simplify and manage access. That experience inspires this series of posts … Read more

Another option for synchronizing JSON Search Indexes is Manual which is enabled by altering the meta-data of the index like this: ALTER INDEX jindex PARAMETERS (‘replace metadata sync (manual)’); Now when DML occurs… INSERT INTO jtable VALUES(‘{“JTOP”:3}’); SELECT * FROM jtable WHERE JSON_EXISTS(jcol,’$.JTOP’); JCOL ——————- {“JTOP”:1} {“JTOP”:2} It will not show up in queries (even … Read more

I was reading this article by Roger Ford and one statement caught my eye “You may notice that if you insert a document but do not commit it, some searches using a search index will not find it, because the index has not yet been synchronized.” I quickly ran a test for this situation. I … Read more

Its time to deal with the inevitable complex changes to the database. I’ll start working through the JSON changes  with this post that handles the following: Non-Unique Patient Names Initially the patient management system was used to maintain Ordering System (OS) and Medical Record Number (MRN) combinations for unique patients (by name). But patient management … Read more

Its time to deal with the inevitable complex changes to the database. I’ll start working through the RDBMS changes  with this post that handles the following: Non-Unique Patient Names Initially the patient management system was used to maintain Ordering System (OS) and Medical Record Number (MRN) combinations for unique patients (by name). But patient management … Read more

JSON_TRANSFORM can ensure JSON structure when records are inserted into the database using an INSTEAD OF INSERT trigger on a view. CREATE OR REPLACE TRIGGER instead_patient INSTEAD OF INSERT ON migrated_patient BEGIN INSERT INTO json_patient VALUES ( JSON_TRANSFORM(:new.migrated, SET ‘$.unique_os’ = OS_LIST_UNIQUE( JSON_QUERY(:new.migrated,’$.mrns[*].OS’ WITH WRAPPER) ) REPLACE ON EXISTING, INSERT ‘$.mrns[*].sdate’ = SYSDATE IGNORE ON … Read more

The JSON_TRANSFORM function is perfect for evolving JSON structures to provide consistency. Take the patient tracking system being used for these posts for example. The first version did not have checks for unique OS values or start and end dates for OS/MRN pairs. Adding these keys is easily done as shown in this example. I can … Read more

My prior posts on JSON_TRANSFORM used simple text values and built-in Oracle functions like SYSDATE. This post demonstrates calling custom PL/SQL functions with JSON_TRANSFORM. Here are the two rows of demo data for this post. The pertinent keys are pname (patient name) and OS (Ordering System) in the elements of the mrns array. SELECT JSON_VALUE … Read more

The simple explanation of the JSON_TRANSFORM SET operation is that it sets values for specified JSON keys. For example “set $.KEY1 to 42′ will set the value of the KEY1 to 42. That’s pretty straightforward. The real power is the additional behaviours that can be defined such as: If $.KEY1 is missing then add it … Read more