Enhancement: Optimize Pax table insertion performance

[gongxun0928]

1. Explicit inline functions.
2. Instead of checking the physical size of the file every time a tuple is inserted, it is checked every 16 tuples.

performance result

create table t1(a int, b int, c int, d int, e text, f text,g text, h text) using pax with(compresstype
=zstd,compresslevel=5);

gpadmin=# insert into t1 select i, i+1,i+2,i+3, i::text, i::text, i::text, i::text from generate_series(1,5000000) i;
INSERT 0 5000000
Time: 6124.535 ms (00:06.125)
gpadmin=# insert into t1 select i, i+1,i+2,i+3, i::text, i::text, i::text, i::text from generate_series(1,5000000) i;
INSERT 0 5000000
Time: 5993.682 ms (00:05.994)

-- optimized with this commit
create table t1(a int, b int, c int, d int, e text, f text,g text, h text) using pax with(compresstype
=zstd,compresslevel=5);
gpadmin=# insert into t1 select i, i+1,i+2,i+3, i::text, i::text, i::text, i::text from generate_series(1,5000000) i;
INSERT 0 5000000
Time: 5713.184 ms (00:05.713)
gpadmin=# insert into t1 select i, i+1,i+2,i+3, i::text, i::text, i::text, i::text from generate_series(1,5000000) i;
INSERT 0 5000000
Time: 5430.221 ms (00:05.430)

Fixes #ISSUE_Number

What does this PR do?

Type of Change

• Bug fix (non-breaking change)
• New feature (non-breaking change)
• Breaking change (fix or feature with breaking changes)
• Documentation update

Breaking Changes

Test Plan

• Unit tests added/updated
• Integration tests added/updated
• Passed make installcheck
• Passed make -C src/test installcheck-cbdb-parallel

Impact

Performance:

User-facing changes:

Dependencies:

Checklist

• Followed contribution guide
• Added/updated documentation
• Reviewed code for security implications
• Requested review from cloudberry committers

Additional Context

CI Skip Instructions

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[jiaqizho]

LGTM with single comment

[jiaqizho]

should be?

  if ((num_tuples_ % PAX_SPLIT_CHECK_INTERVAL) == 0) {
    cur_physical_size_ = writer_->PhysicalSize();
    if (strategy_->ShouldSplit(cur_physical_size_, num_tuples_)) {
      ... 
    }
  }

[gongxun0928]

Because of the CTID constraint, we have to strictly enforce the accuracy of the tuple count and make sure it doesn't exceed PAX_MAX_NUM_TUPLES_PER_FILE. That's why we kept this precise check here.

On the other hand, the biggest performance hit here is the PhysicalSize() function. So to reduce the overhead of calling it so often, we only check the file size every PAX_SPLIT_CHECK_INTERVAL tuples.