COPY导入优化

--显示为SSE 4.2 supported表示支持
[omm3@hostname ~]$ grep -q sse4_2 /proc/cpuinfo && echo "SSE 4.2 supported" || echo "SSE 4.2 not supported"
SSE 4.2 supported

--显示为SSE 4.2 supported表示不支持
[xxxx@hostname ~]$ grep -q sse4_2 /proc/cpuinfo && echo "SSE 4.2 supported" || echo "SSE 4.2 not supported"
SSE 4.2 not supported

[omm3@hostname ~]$ gsql -d postgres -p18000
gsql ((MogDB 3.0.0 build 945141ad) compiled at 2022-05-28 16:14:02 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

MogDB=# set enable_sse42 to on;
SET
MogDB=# show enable_sse42;
enable_sse42 
--------------
 on
(1 row)

MogDB=# set enable_sse42 to off;
SET
MogDB=# show enable_sse42;
enable_sse42 
--------------
off
(1 row)