確定表的存儲(chǔ)格式

Hologres支持行存、列存、行列共存三種存儲(chǔ)格式，具體原理及使用建議請(qǐng)參見(jiàn)表存儲(chǔ)格式：列存、行存、行列共存。

首先請(qǐng)參考下圖所示流程確定您表的存儲(chǔ)格式。如果您的業(yè)務(wù)場(chǎng)景尚未完全明確，請(qǐng)優(yōu)先選擇行列共存，以兼顧更多可能出現(xiàn)的場(chǎng)景。

確定表的查詢(xún)屬性

在確定表的存儲(chǔ)格式后，您需要根據(jù)查詢(xún)場(chǎng)景確定表的屬性。

（可選）確定表所屬的Table Group

如果您的實(shí)例規(guī)格較大（大于256 Core），并且業(yè)務(wù)場(chǎng)景較豐富，可以考慮規(guī)劃多個(gè)Table Group，并在建表時(shí)指定表所屬的Table Group。詳情請(qǐng)參見(jiàn)Table Group設(shè)置最佳實(shí)踐。

附錄：建表語(yǔ)句

• 場(chǎng)景1 DDL：

  -- 有主鍵表DDL如下。無(wú)主鍵表只需刪去O_ORDERKEY的PRIMARY KEY定義。
  DROP TABLE IF EXISTS orders;
  BEGIN;
  CREATE TABLE orders(
      O_ORDERKEY       BIGINT         NOT NULL PRIMARY KEY
      ,O_CUSTKEY       INT            NOT NULL
      ,O_ORDERSTATUS   TEXT           NOT NULL
      ,O_TOTALPRICE    DECIMAL(15,2)  NOT NULL
      ,O_ORDERDATE     TIMESTAMPTZ    NOT NULL
      ,O_ORDERPRIORITY TEXT           NOT NULL
      ,O_CLERK         TEXT           NOT NULL
      ,O_SHIPPRIORITY  INT            NOT NULL
      ,O_COMMENT       TEXT           NOT NULL
  );
  CALL SET_TABLE_PROPERTY('orders', 'orientation', 'row');
  CALL SET_TABLE_PROPERTY('orders', 'clustering_key', 'o_orderkey');
  CALL SET_TABLE_PROPERTY('orders', 'distribution_key', 'o_orderkey');
  COMMIT;

• 場(chǎng)景2 DDL：

  -- 創(chuàng)建滿足上文表屬性組合的Lineitem表。
  DROP TABLE IF EXISTS lineitem;
  BEGIN;
  CREATE TABLE lineitem
  (
      L_ORDERKEY      BIGINT      NOT NULL,
      L_PARTKEY       INT         NOT NULL,
      L_SUPPKEY       INT         NOT NULL,
      L_LINENUMBER    INT         NOT NULL,
      L_QUANTITY      DECIMAL(15,2) NOT NULL,
      L_EXTENDEDPRICE DECIMAL(15,2) NOT NULL,
      L_DISCOUNT      DECIMAL(15,2) NOT NULL,
      L_TAX           DECIMAL(15,2) NOT NULL,
      L_RETURNFLAG    TEXT        NOT NULL,
      L_LINESTATUS    TEXT        NOT NULL,
      L_SHIPDATE      TIMESTAMPTZ NOT NULL,
      L_COMMITDATE    TIMESTAMPTZ NOT NULL,
      L_RECEIPTDATE   TIMESTAMPTZ NOT NULL,
      L_SHIPINSTRUCT  TEXT        NOT NULL,
      L_SHIPMODE      TEXT        NOT NULL,
      L_COMMENT       TEXT        NOT NULL,
      PRIMARY KEY (L_ORDERKEY,L_LINENUMBER)
  );
  CALL set_table_property('lineitem', 'orientation', 'row');
  -- CALL set_table_property('lineitem', 'clustering_key', 'L_ORDERKEY,L_SHIPDATE');
  CALL set_table_property('lineitem', 'distribution_key', 'L_ORDERKEY');
  COMMIT;

• 場(chǎng)景3 DDL：

  -- 創(chuàng)建Lineitem分區(qū)表。非分區(qū)表同場(chǎng)景2。
  DROP TABLE IF EXISTS lineitem;
  BEGIN;
  CREATE TABLE lineitem
  (
      L_ORDERKEY      BIGINT      NOT NULL,
      L_PARTKEY       INT         NOT NULL,
      L_SUPPKEY       INT         NOT NULL,
      L_LINENUMBER    INT         NOT NULL,
      L_QUANTITY      DECIMAL(15,2) NOT NULL,
      L_EXTENDEDPRICE DECIMAL(15,2) NOT NULL,
      L_DISCOUNT      DECIMAL(15,2) NOT NULL,
      L_TAX           DECIMAL(15,2) NOT NULL,
      L_RETURNFLAG    TEXT        NOT NULL,
      L_LINESTATUS    TEXT        NOT NULL,
      L_SHIPDATE      TIMESTAMPTZ NOT NULL,
      L_COMMITDATE    TIMESTAMPTZ NOT NULL,
      L_RECEIPTDATE   TIMESTAMPTZ NOT NULL,
      L_SHIPINSTRUCT  TEXT        NOT NULL,
      L_SHIPMODE      TEXT        NOT NULL,
      L_COMMENT       TEXT        NOT NULL,
      L_YEAR          TEXT        NOT NULL,
      PRIMARY KEY (L_ORDERKEY,L_LINENUMBER,L_YEAR)
  )
  PARTITION BY LIST (L_YEAR);
  CALL set_table_property('lineitem', 'clustering_key', 'L_ORDERKEY,L_SHIPDATE');
  CALL set_table_property('lineitem', 'segment_key', 'L_SHIPDATE');
  CALL set_table_property('lineitem', 'distribution_key', 'L_ORDERKEY');
  COMMIT;

• 場(chǎng)景4 DDL：

  -- 創(chuàng)建設(shè)置不恰當(dāng)表屬性的Lineitem表。對(duì)比場(chǎng)景只需將clustering_key和bitmap_columns改為恰當(dāng)值。
  DROP TABLE IF EXISTS lineitem;
  BEGIN;
  CREATE TABLE lineitem
  (
      L_ORDERKEY      BIGINT      NOT NULL,
      L_PARTKEY       INT         NOT NULL,
      L_SUPPKEY       INT         NOT NULL,
      L_LINENUMBER    INT         NOT NULL,
      L_QUANTITY      DECIMAL(15,2) NOT NULL,
      L_EXTENDEDPRICE DECIMAL(15,2) NOT NULL,
      L_DISCOUNT      DECIMAL(15,2) NOT NULL,
      L_TAX           DECIMAL(15,2) NOT NULL,
      L_RETURNFLAG    TEXT        NOT NULL,
      L_LINESTATUS    TEXT        NOT NULL,
      L_SHIPDATE      TIMESTAMPTZ NOT NULL,
      L_COMMITDATE    TIMESTAMPTZ NOT NULL,
      L_RECEIPTDATE   TIMESTAMPTZ NOT NULL,
      L_SHIPINSTRUCT  TEXT        NOT NULL,
      L_SHIPMODE      TEXT        NOT NULL,
      L_COMMENT       TEXT        NOT NULL,
      PRIMARY KEY (L_ORDERKEY,L_LINENUMBER)
  );
  CALL set_table_property('lineitem', 'segment_key', 'L_SHIPDATE');
  CALL set_table_property('lineitem', 'distribution_key', 'L_ORDERKEY');
  CALL set_table_property('lineitem', 'bitmap_columns', 'l_orderkey,l_partkey,l_suppkey,l_linenumber,l_returnflag,l_linestatus,l_shipinstruct,l_comment');
  COMMIT;

• 場(chǎng)景5 DDL：

  -- 將Group By字段設(shè)為distribution_key的Lineitem表。
  DROP TABLE IF EXISTS lineitem;
  BEGIN;
  CREATE TABLE lineitem
  (
      L_ORDERKEY      BIGINT      NOT NULL,
      L_PARTKEY       INT         NOT NULL,
      L_SUPPKEY       INT         NOT NULL,
      L_LINENUMBER    INT         NOT NULL,
      L_QUANTITY      DECIMAL(15,2) NOT NULL,
      L_EXTENDEDPRICE DECIMAL(15,2) NOT NULL,
      L_DISCOUNT      DECIMAL(15,2) NOT NULL,
      L_TAX           DECIMAL(15,2) NOT NULL,
      L_RETURNFLAG    TEXT        NOT NULL,
      L_LINESTATUS    TEXT        NOT NULL,
      L_SHIPDATE      TIMESTAMPTZ NOT NULL,
      L_COMMITDATE    TIMESTAMPTZ NOT NULL,
      L_RECEIPTDATE   TIMESTAMPTZ NOT NULL,
      L_SHIPINSTRUCT  TEXT        NOT NULL,
      L_SHIPMODE      TEXT        NOT NULL,
      L_COMMENT       TEXT        NOT NULL,
      PRIMARY KEY (L_ORDERKEY,L_LINENUMBER,L_SUPPKEY)
  );
  CALL set_table_property('lineitem', 'segment_key', 'L_COMMITDATE');
  CALL set_table_property('lineitem', 'clustering_key', 'L_ORDERKEY,L_SHIPDATE');
  CALL set_table_property('lineitem', 'distribution_key', 'L_SUPPKEY');
  COMMIT;

• 場(chǎng)景6 DDL：

  DROP TABLE IF EXISTS LINEITEM;
  
  BEGIN;
  CREATE TABLE LINEITEM
  (
      L_ORDERKEY      BIGINT      NOT NULL,
      L_PARTKEY       INT         NOT NULL,
      L_SUPPKEY       INT         NOT NULL,
      L_LINENUMBER    INT         NOT NULL,
      L_QUANTITY      DECIMAL(15,2) NOT NULL,
      L_EXTENDEDPRICE DECIMAL(15,2) NOT NULL,
      L_DISCOUNT      DECIMAL(15,2) NOT NULL,
      L_TAX           DECIMAL(15,2) NOT NULL,
      L_RETURNFLAG    TEXT        NOT NULL,
      L_LINESTATUS    TEXT        NOT NULL,
      L_SHIPDATE      TIMESTAMPTZ NOT NULL,
      L_COMMITDATE    TIMESTAMPTZ NOT NULL,
      L_RECEIPTDATE   TIMESTAMPTZ NOT NULL,
      L_SHIPINSTRUCT  TEXT        NOT NULL,
      L_SHIPMODE      TEXT        NOT NULL,
      L_COMMENT       TEXT        NOT NULL,
      PRIMARY KEY (L_ORDERKEY,L_LINENUMBER)
  );
  CALL set_table_property('LINEITEM', 'clustering_key', 'L_SHIPDATE,L_ORDERKEY');
  CALL set_table_property('LINEITEM', 'segment_key', 'L_SHIPDATE');
  CALL set_table_property('LINEITEM', 'distribution_key', 'L_ORDERKEY');
  CALL set_table_property('LINEITEM', 'bitmap_columns', 'L_ORDERKEY,L_PARTKEY,L_SUPPKEY,L_LINENUMBER,L_RETURNFLAG,L_LINESTATUS,L_SHIPINSTRUCT,L_SHIPMODE,L_COMMENT');
  CALL set_table_property('LINEITEM', 'dictionary_encoding_columns', 'L_RETURNFLAG,L_LINESTATUS,L_SHIPINSTRUCT,L_SHIPMODE,L_COMMENT');
  COMMIT;
  
  DROP TABLE IF EXISTS ORDERS;
  
  BEGIN;
  CREATE TABLE ORDERS
  (
      O_ORDERKEY      BIGINT      NOT NULL PRIMARY KEY,
      O_CUSTKEY       INT         NOT NULL,
      O_ORDERSTATUS   TEXT        NOT NULL,
      O_TOTALPRICE    DECIMAL(15,2) NOT NULL,
      O_ORDERDATE     timestamptz NOT NULL,
      O_ORDERPRIORITY TEXT        NOT NULL,
      O_CLERK         TEXT        NOT NULL,
      O_SHIPPRIORITY  INT         NOT NULL,
      O_COMMENT       TEXT        NOT NULL
  );
  CALL set_table_property('ORDERS', 'segment_key', 'O_ORDERDATE');
  CALL set_table_property('ORDERS', 'distribution_key', 'O_ORDERKEY');
  CALL set_table_property('ORDERS', 'bitmap_columns', 'O_ORDERKEY,O_CUSTKEY,O_ORDERSTATUS,O_ORDERPRIORITY,O_CLERK,O_SHIPPRIORITY,O_COMMENT');
  CALL set_table_property('ORDERS', 'dictionary_encoding_columns', 'O_ORDERSTATUS,O_ORDERPRIORITY,O_CLERK,O_COMMENT');
  COMMIT;