Creating a DLI Table and Associating It with CSS

Function

This statement is used to create a DLI table and associate it with an existing CSS table.

In Spark cross-source development scenarios, there is a risk of password leakage if datasource authentication information is directly configured. You are advised to use the datasource authentication provided by DLI.

For details about datasource authentication, see Introduction to Datasource Authentication.

Prerequisites

Before creating a DLI table and associating it with CSS, you need to create a datasource connection. For operations on the management console, see Enhanced Datasource Connections.

Syntax

    
         CREATE TABLE [IF NOT EXISTS] TABLE_NAME(
  FIELDNAME1 FIELDTYPE1,
  FIELDNAME2 FIELDTYPE2)
  USING CSS OPTIONS (
  'es.nodes'='xx',
  'resource'='type_path_in_CSS',
  'pushdown'='true',
  'strict'='false',
  'batch.size.entries'= '1000',
  'batch.size.bytes'= '1mb',
  'es.nodes.wan.only' = 'true',
  'es.mapping.id' = 'FIELDNAME');

Keywords

**Table 1** CREATE TABLE keywords
Parameter	Description
es.nodes	Create a datasource connection before you can obtain this CSS connection address. For operations on the management console, see Enhanced Datasource Connections. If you have created an enhanced datasource connection, you can use the internal IP address provided by CSS. The format is **IP1:PORT1,IP2:PORT2**.
resource	The resource is used to specify the CSS datasource connection name. You can use /index/type to specify the resource location (for easier understanding, the index can be seen as database and type as table). NOTE: In ES 6.X, a single index supports only one type, and the type name can be customized. In ES 7.X, a single index uses _doc as the type name and cannot be customized. To access ES 7.X, set this parameter to index.
pushdown	Indicates whether the press function of CSS is enabled. The default value is set to true. If there are a large number of I/O transfer tables, the pushdown can be enabled to reduce I/Os when the where filtering conditions are met.
strict	Indicates whether the CSS pushdown is strict. The default value is set to false. In exact match scenarios, more I/Os are reduced than pushdown.
batch.size.entries	Maximum number of entries that can be inserted to a batch processing. The default value is 1000. If the size of a single data record is so large that the number of data records in the bulk storage reaches the upper limit of the data amount of a single batch processing, the system stops storing data and submits the data based on the batch.size.bytes.
batch.size.bytes	Maximum amount of data in a single batch processing. The default value is 1 MB. If the size of a single data record is so small that the number of data records in the bulk storage reaches the upper limit of the data amount of a single batch processing, the system stops storing data and submits the data based on the batch.size.entries.
es.nodes.wan.only	Indicates whether to access the Elasticsearch node using only the domain name. The default value is false. If the original internal IP address provided by CSS is used as the es.nodes, you do not need to set this parameter or set it to false.
es.mapping.id	Specifies a field whose value is used as the document ID in the Elasticsearch node. NOTE: The document ID in the same /index/type is unique. If a field that functions as a document ID has duplicate values, the document with the duplicate ID will be overwritten when the ES is inserted. This feature can be used as a fault tolerance solution. When data is being inserted, the DLI job fails and some data has been inserted into Elasticsearch. The data is redundant. If Document id is set, the last redundant data will be overwritten when the DLI job is executed again.
es.net.ssl	Whether to connect to the secure CSS cluster. The default value is false.
es.certificate.name	Name of the datasource authentication used to connect to the secure CSS cluster. For details about how to create datasource authentication, see Datasource Authentication in the Data Lake Insight User Guide.

batch.size.entries and batch.size.bytes limit the number of data records and data volume respectively.

Example

    
         CREATE TABLE IF NOT EXISTS dli_to_css (doc_id String, name string, age int)
  USING CSS OPTIONS (
  es.nodes 'to-css-1174404703-LzwpJEyx.datasource.com:9200',
  resource '/dli_index/dli_type',
  pushdown 'false',
  strict 'true',
  es.nodes.wan.only 'true',
  es.mapping.id 'doc_id');