Docs: minor edits and fixes.
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<title id="iw157419">About the Greenplum Architecture</title>
- <shortdesc>Greenplum Database is a massively parallel processing (MPP) database server
- with an architecture specially designed to manage large-scale analytic data warehouses and
- business intelligence workloads. </shortdesc>
+ <shortdesc>Greenplum Database is a massively parallel processing (MPP) database server with an
+ architecture specially designed to manage large-scale analytic data warehouses and business
+ intelligence workloads. </shortdesc>
<body>
<p id="iw157381">MPP (also known as a <i>shared nothing</i> architecture) refers to systems with
two or more processors that cooperate to carry out an operation, each processor with its own
PostgreSQL disk-oriented database instances acting together as one cohesive database
management system (DBMS). It is based on PostgreSQL 8.3.23, and in most cases is very similar
to PostgreSQL with regard to SQL support, features, configuration options, and end-user
- functionality. Database users interact with Greenplum Database as they would a regular
+ functionality. Database users interact with Greenplum Database as they would with a regular
PostgreSQL DBMS. </p>
<p>Greenplum Database can use the append-optimized (AO) storage format for bulk loading and
reading of data, and provides performance advantages over HEAP tables. Append-optimized
which store and process the data.</p>
<fig id="iw157440">
<title>High-Level Greenplum Database Architecture</title>
- <image height="316px" href="../graphics/highlevel_arch.jpg" placement="break" width="397px"
- />
+ <image height="316px" href="../graphics/highlevel_arch.jpg" placement="break" width="397px"/>
</fig>
<p>The following topics describe the components that make up a Greenplum Database system and how
they work together. <ul id="ul_cz4_xhy_dq" otherprops="op-help">
<body>
<p>Greenplum Database end-users interact with Greenplum Database (through the master) as they
would with a typical PostgreSQL database. They connect to the database using client programs
- such as <codeph>psql</codeph> or application programming interfaces (APIs) such as JDBC or
- ODBC.</p>
+ such as <codeph>psql</codeph> or application programming interfaces (APIs) such as JDBC,
+ ODBC or <xref href="https://www.postgresql.org/docs/8.3/static/libpq.html" format="html"
+ scope="external">libpq</xref> (the PostgreSQL C API).</p>
<p>The master is where the <i>global system catalog</i> resides. The global system catalog is
the set of system tables that contain metadata about the Greenplum Database system itself.
The master does not contain any user data; data resides only on the <i>segments</i>. The
<body>
<p>The <i>interconnect</i> refers to the inter-process communication between segments and the
network infrastructure on which this communication relies. The Greenplum interconnect uses a
- standard Ethernet switching fabric. For performance reasons, a 10-Gigabit system, or faster, is recommended.</p>
+ standard Ethernet switching fabric. For performance reasons, a 10-Gigabit system, or faster,
+ is recommended.</p>
<p>By default, the interconnect uses User Datagram Protocol with flow control (UDPIFC) for
interconnect traffic to send messages over the network. The Greenplum software performs
packet verification beyond what is provided by UDP. This means the reliability is equivalent
