Add readme notes

danolivo · danolivo · commit f1a28802878d · 2019-01-08T22:52:16.000+05:00
diff --git a/README.md b/README.md
@@ -1,7 +1,12 @@
 # execplan
-PostgreSQL Extension for raw query plan execution
+PostgreSQL patch & extension for raw query plan execution
 
-This project dedicated to parallel query execution problem.
+This project dedicated to query execution problem in DBMS for computing systems with cluster architecture.
 
-Parallel DBMS needs to execute an identical query plan at each computing node. It is needed for tuples redistribution during a query.
-Today PostgreSQL can process only SQL strings. But it is not guaranteed, that the planner at each node will construct same query plan, because different statistics, relation sizes e.t.c.
+The DBMS may need to execute an identical query plan at each computing node.
+Today PostgreSQL can process only SQL statements. But it is not guaranteed, that the planner at each node will construct same query plan, because different statistics, relation sizes e.t.c.
+
+This solution based on postgres-xl approach: plan tree is serialized by the nodeToString() routine.
+Further, the serialized plan transfer by new libpq routine called `PQsendPlan`.
+In this project we use postgres_fdw connections for management of sessions and remote transactions.
+Some `repeater` extension used for the demonstration of plan transfer machinery.
