readme edits postgres#24

Author: kelvich

README.md

@@ -6,6 +6,17 @@ disaster recovery.
 
 
 
+## Features
+
+* Cluster-wide transaction isolation
+* Synchronous logical replication
+* DDL Replication
+* Distributed sequences
+* Fault tolerance
+* Automatic node recovery
+
+
+
 ## Overview
 
 Multi-master replicates same database to all nodes in cluster and allows writes to each node. Transaction
@@ -16,13 +27,6 @@ commit latency for amount of time proportional to roundtrip between nodes nedded
 transactions and queries executed locally without measurable overhead. Replication mechanism itself based on
 logical decoding and earlier version of pglogical extension provided for community by 2ndQuadrant team.
 
-Several changes was made in postgres core to implement mentioned functionality:
-* Transaction manager API. (eXtensible Transaction Manager, xtm). Generic interface to plug distributed
-transaction engines.  More info on [postgres wiki](https://wiki.postgresql.org/wiki/DTM) and
-on [the email thread](http://www.postgresql.org/message-id/flat/F2766B97-555D-424F-B29F-E0CA0F6D1D74@postgrespro.ru).
-* Distributed deadlock detection API.
-* Logical decoding of transactions.
-
 Cluster consisting of N nodes can continue to work while majority of initial nodes are alive and reachable by
 other nodes. This is done by using 3 phase commit protocol and heartbeats for failure discovery. Node that is
 brought back to cluster can be fast-forwaded to actual state automatically in case when transactions log still
@@ -32,38 +36,6 @@ Read more about internals on [Architechture](/Architechture) page.
 
 
 
-## Features
-
-* Cluster-wide transaction isolation
-* Synchronous logical replication
-* DDL Replication
-* Distributed sequences
-* Fault tolerance
-* Automatic node recovery
-
-
-
-## Limitations
-
-* Commit latency.
-Current implementation of logical replication sends data to subscriber nodes only after local commit, so in case of
-heavy-write transaction user will wait for transaction processing two times: on local node and al other nodes
-(simultaneosly). We have plans to address this issue in future.
-
-* DDL replication.
-While data is replicated on logical level, DDL replicated by statements performing distributed commit with the same
-statement. Some complex DDL scenarious including stored procedures and temp temp tables aren't working properly. We
-are working right now on proving full compatibility with ordinary postgres. Currently we are passing 141 of 164
-postgres regression tests.
-
-* Isolation level.
-Multimaster currently support only _repeatable_ _read_ isolation level. This is stricter than default _read_commited_,
-but also increases probability of serialization failure during commit. _Serializable_ level isn't supported yet.
-
-* One database per cluster.
-
-
-
 ## Installation
 
 (Existing db?)
@@ -149,7 +121,7 @@ After things go more stable we will release prebuilt packages for major platform
  multimaster.heartbeat_send_timeout = 250
  multimaster.ignore_tables_without_pk = true
  multimaster.twopc_min_timeout = 2000
- ```
+```
 1. Allow replication in `pg_hba.conf`.
 
 (link to full doc on config params)
@@ -188,6 +160,27 @@ To run tests:
 * `make -C contrib/mmts xcheck` to run blockade tests. The blockade tests require `docker`, `blockade`, and some other packages installed, see [requirements.txt](tests2/requirements.txt) for the list. You might also want to gain superuser privileges to run these tests successfully.
 
 
+## Limitations
+
+* Commit latency.
+Current implementation of logical replication sends data to subscriber nodes only after local commit, so in case of
+heavy-write transaction user will wait for transaction processing two times: on local node and al other nodes
+(simultaneosly). We have plans to address this issue in future.
+
+* DDL replication.
+While data is replicated on logical level, DDL replicated by statements performing distributed commit with the same
+statement. Some complex DDL scenarious including stored procedures and temp temp tables aren't working properly. We
+are working right now on proving full compatibility with ordinary postgres. Currently we are passing 141 of 164
+postgres regression tests.
+
+* Isolation level.
+Multimaster currently support only _repeatable_ _read_ isolation level. This is stricter than default _read_ _commited_,
+but also increases probability of serialization failure during commit. _Serializable_ level isn't supported yet.
+
+* One database per cluster.
+
+
+
 docs:
 
 ## Architechture