功能介紹

Oracle數(shù)據(jù)庫(kù)在創(chuàng)建sequence的時(shí)候可以支持設(shè)置maxvalue 為9999999999999999999999999999，這樣的SQL在LightDB23.3版本之前都是執(zhí)行失敗的。為了方便Oracle用戶遷移到LightDB上，在LightDB23.3版本上，增加了sequence支持maxvalue設(shè)置為9999999999999999999999999999的語(yǔ)法兼容。
如果設(shè)置的maxvalue的值大于INT64_MAX（9223372036854775807），則設(shè)置maxvalue為sequence類型所對(duì)應(yīng)的最大值。

使用說(shuō)明

1. 創(chuàng)建sequence時(shí)設(shè)置maxvalue為9999999999999999999999999999

lightdb@lt_test=# create sequence s1 maxvalue 9999999999999999999999999999;
CREATE SEQUENCE
lightdb@lt_test=# \d+ s1Sequence "public.s1"Type  | Start | Minimum |       Maximum       | Increment | Cycles? | Cache 
--------+-------+---------+---------------------+-----------+---------+-------bigint |     1 |       1 | 9223372036854775807 |         1 | no      |     1lightdb@lt_test=# 

2. 修改sequence時(shí)設(shè)置maxvalue為9999999999999999999999999999

lightdb@lt_test=# create sequence s2 maxvalue 100000;
CREATE SEQUENCE
lightdb@lt_test=# \d+ s2Sequence "public.s2"Type  | Start | Minimum | Maximum | Increment | Cycles? | Cache 
--------+-------+---------+---------+-----------+---------+-------bigint |     1 |       1 |  100000 |         1 | no      |     1lightdb@lt_test=# 
lightdb@lt_test=# alter sequence s2 maxvalue 9999999999999999999999999999;
ALTER SEQUENCE
lightdb@lt_test=# \d+ s2Sequence "public.s2"Type  | Start | Minimum |       Maximum       | Increment | Cycles? | Cache 
--------+-------+---------+---------------------+-----------+---------+-------bigint |     1 |       1 | 9223372036854775807 |         1 | no      |     1lightdb@lt_test=# 

3. 當(dāng)sequence類型為smallint時(shí)，設(shè)置maxvalue為9999999999999999999999999999

lightdb@lt_test=# create sequence s3 as smallint maxvalue 1000;
CREATE SEQUENCE
lightdb@lt_test=# \d+ s3Sequence "public.s3"Type   | Start | Minimum | Maximum | Increment | Cycles? | Cache 
----------+-------+---------+---------+-----------+---------+-------smallint |     1 |       1 |    1000 |         1 | no      |     1lightdb@lt_test=# alter sequence s3 maxvalue 9999999999999999999999999999;
ALTER SEQUENCE
lightdb@lt_test=# \d+ s3Sequence "public.s3"Type   | Start | Minimum | Maximum | Increment | Cycles? | Cache 
----------+-------+---------+---------+-----------+---------+-------smallint |     1 |       1 |   32767 |         1 | no      |     1lightdb@lt_test=#