postgresql 13 数据库 sequence 的 maxvalue 最大值是多少?

朴灿烈づ我的快乐病毒、 2022-12-15 03:53 171阅读 0赞

os: centos 7.8.2003  
db: postgresql 13.0

# 版本 #

# cat /etc/centos-release
    CentOS Linux release 7.8.2003 (Core)
    # su - postgres
    Last login: Thu Oct 15 09:59:33 CST 2020 on pts/1
    
    ppostgres@nodepg13-> psql -c "select version();"
                                                     version                                                 
    ---------------------------------------------------------------------------------------------------------
     PostgreSQL 13.0 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39), 64-bit
    (1 row)

# create sequence #

$ psql
    
    postgres=# create sequence seq_1;
    CREATE SEQUENCE
    postgres=# select c.relname,c.relkind,s.* from pg_class c,pg_sequence s where c.oid=s.seqrelid;
     relname | relkind | seqrelid | seqtypid | seqstart | seqincrement |       seqmax        | seqmin | seqcache | seqcycle 
    ---------+---------+----------+----------+----------+--------------+---------------------+--------+----------+----------
     seq_1   | S       |    40968 |       20 |        1 |            1 | 9223372036854775807 |      1 |        1 | f
    (1 row)

seqmax = 9223372036854775807

maxvalue  
NO MAXVALUE  
The optional clause MAXVALUE maxvalue determines the maximum value for the sequence. If this clause is not supplied or NO MAXVALUE is specified, then default values will be used. The default for an ascending sequence is the maximum value of the data type. The default for a descending sequence is -1.

那就需要查看下 bigint 的值

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2N0eXB5YjIwMDI_size_16_color_FFFFFF_t_70_pic_center]

参考：  
https://www.postgresql.org/docs/13/sql-createsequence.html  
https://www.postgresql.org/docs/13/datatype-numeric.html

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