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joplin notion extension/Web Development/sql/extras.md

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+extras
+
+- pocketbase : for small projects
+- Conflict-Free Replicated Data Type: A conflict-free replicated data type (CRDT) is a special distributed data structure that lets multiple computers store, update, and sync copies of data independently without needing a central coordinator or locking mechanism
+- last write wins
+
+```txt
+  there is a table name tab and it contains a column name col.
+
+now this database is in both devices and is same too. values in column 'col' of table 'tab' in both database are A.B,C which is last modified at 5pm
+
+in device1 changes being made and now its value is X,B . this database is last updated at 6pm
+in device2 changes being made and now its value is Y,C. this database is last updated at 7pm
+
+now how to sync the changes?
+in first one, A is replaced with X, C is deleted
+in 2nd one, A is replaced with Y, B is deleted
+
+so total changes are
+A -> X
+C -> gone
+A -> Y
+B -> gone
+
+here A being updated to either X and Y is decided by time so latest one ie 7pm one win and A->Y, B and C are deleted
+so finally it will be Y
+```