Optimize code of IVM and fix some typos #569

Job	Run time
check-skip	1s
Build Apache Cloudberry	9m 28s
prepare-test-matrix	7s
RPM Install Test Apache Cloudberry	49s
ic-good-opt-off	25m 25s
ic-good-opt-on	29m 43s
ic-expandshrink	2m 47s
ic-singlenode	6m 33s
ic-resgroup-v2	18m 2s
ic-contrib	2m 19s
ic-gpcontrib	2m 42s
ic-fixme	1m 55s
ic-isolation2	23m 2s
ic-isolation2-crash	3m 0s
ic-parallel-retrieve-cursor	2m 59s
Generate Apache Cloudberry Build Report	1s
	2h 8m 53s

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