Do you require distributed consistency? – What isolation level is being used? • Will there be a node at a remote location? – What is acceptable latency? – What is acceptable in a network partition? with 31 cores largely idle • Prior to 9.6, one work-around for this would be to configure a multi- node Postgres-XL “cluster” on the same server, which would utilize the other cores • PostgreSQL 9.6 adds DELETEs • Progress towards federating PostgreSQL servers • Potential consistency issues • No direct node-to-node row shipping • No replicated table handling • Can be ok for simple queries- SELECT COUNT(*)

structure, you could write CREATE TABLE tree ( node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... ); A top-level node would have NULL parent_id, but non-NULL parent_id the more permissive “document node”1 of the XQuery and XPath data model. Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS the root node of an XML value. If a version is specified, it replaces the value in the root node's version declaration; if a standalone setting is specified, it replaces the value in the root node's standalone

could write CREATE TABLE tree ( node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... 61 Data Definition ); A top-level node would have NULL parent_id, but non-NULL the more permissive “document node”1 of the XQuery and XPath data model. Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS the root node of an XML value. If a version is specified, it replaces the value in the root node's version declaration; if a standalone setting is specified, it replaces the value in the root node's standalone

structure, you could write CREATE TABLE tree ( node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... ); A top-level node would have NULL parent_id, while non-NULL parent_id standard, as well as “content” fragments, which are defined by reference to the more permissive “document node”3 of the XQuery and 2 https://tools.ietf.org/html/rfc4122 3 https://www.w3.org/TR/2010/REC-xpath Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS DOCUMENT can be used to evaluate whether a particular xml value is a full

structure, you could write CREATE TABLE tree ( node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... ); A top-level node would have NULL parent_id, while non-NULL parent_id the more permissive “document node”3 of the XQuery and XPath data model. Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS the root node of an XML value. If a version is specified, it replaces the value in the root node's version declaration; if a standalone setting is specified, it replaces the value in the root node's standalone

CREATE TABLE tree ( 71 Data Definition node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... ); A top-level node would have NULL parent_id, but non-NULL parent_id enable_partition_pruning setting. Note Execution-time partition pruning currently only occurs for the Append node type, not for MergeAppend or ModifyTable nodes. That is likely to be changed in a future release of the more permissive “document node”1 of the XQuery and XPath data model. Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS

structure, you could write CREATE TABLE tree ( node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... ); A top-level node would have NULL parent_id, but non-NULL parent_id enable_partition_pruning setting. Note Execution-time partition pruning currently only occurs for the Append node type, not for MergeAppend or ModifyTable nodes. That is likely to be changed in a future release of the more permissive “document node”1 of the XQuery and XPath data model. Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS

structure, you could write CREATE TABLE tree ( node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... ); A top-level node would have NULL parent_id, but non-NULL parent_id partition pruning currently only occurs for the Append and MergeAppend node types. It is not yet implemented for the ModifyTable node type, but that is likely to be changed in a future release of PostgreSQL the more permissive “document node”1 of the XQuery and XPath data model. Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS

72 Data Definition CREATE TABLE tree ( node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... ); A top-level node would have NULL parent_id, but non-NULL parent_id partition pruning currently only occurs for the Append and MergeAppend node types. It is not yet implemented for the ModifyTable node type, but that is likely to be changed in a future release of PostgreSQL the more permissive “document node”1 of the XQuery and XPath data model. Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS

structure, you could write CREATE TABLE tree ( node_id integer PRIMARY KEY, parent_id integer REFERENCES tree, name text, ... ); A top-level node would have NULL parent_id, but non-NULL parent_id partition pruning currently only occurs for the Append and MergeAppend node types. It is not yet implemented for the ModifyTable node type, but that is likely to be changed in a future release of PostgreSQL the more permissive “document node”1 of the XQuery and XPath data model. Roughly, this means that content fragments can have more than one top-level element or character node. The expression xmlvalue IS