Good to go. I think the OpenTable can be pass opt instead of individual fields, but that can be done later. Just add a TODO.

Reviewed 1 of 9 files at r5, 9 of 12 files at r6, 4 of 4 files at r7.
Reviewable status: 13 of 14 files reviewed, 27 unresolved discussions (waiting on @ashish-goswami, @golangcibot, @jarifibrahim, and @manishrjain)

db.go, line 918 at r7 (raw file):

	}

	tbl, err := table.OpenTable(fd, db.opt.TableLoadingMode, db.opt.ChecksumVerificationMode)

Add a todo to pass the opt object instead of specific fields.

table/table.go, line 293 at r7 (raw file):

}

func (t *Table) block(idx int) (block, error) {

Wouldn't it make sense for this to return a pointer to block? That might be cheaper than getting all the block fields copied over.

Reviewable status: 13 of 14 files reviewed, 21 unresolved discussions (waiting on @ashish-goswami, @golangcibot, and @manishrjain)

table/table_test.go, line 657 at r8 (raw file):

	n := int(5 * 1e6)
	tbl := getTableForBenchmarks(b, n)
	// defer tbl.DecrRef()

Uncomment please!

table/table_test.go, line 658 at r8 (raw file):

	tbl := getTableForBenchmarks(b, n)
	// defer tbl.DecrRef()
	fmt.Println("********** ", tbl.Size())

Can we remove this?

Reviewable status: 12 of 14 files reviewed, 9 unresolved discussions (waiting on @golangcibot, @jarifibrahim, @manishrjain, and @martinmr)

db.go, line 918 at r7 (raw file):

Done.

options.go, line 155 at r5 (raw file):

Ok. I will take care of this.

table/builder.go, line 187 at r5 (raw file):

Done.

table/table.go, line 310 at r6 (raw file):

Done.

table/table.go, line 293 at r7 (raw file):

Done.

table/table.go, line 345 at r9 (raw file):

Done.

table/table_test.go, line 657 at r8 (raw file):

Done.

table/table_test.go, line 658 at r8 (raw file):

Done.

Reviewed 1 of 2 files at r9, 1 of 1 files at r10.
Reviewable status: all files reviewed, 7 unresolved discussions (waiting on @golangcibot, @jarifibrahim, and @manishrjain)

Reviewable status: all files reviewed, 10 unresolved discussions (waiting on @ashish-goswami, @golangcibot, and @manishrjain)

db.go, line 463 at r10 (raw file):

// VerifyChecksum verifies checksum for all tables on all levels.
// This method can be used to verify checksum, if ChecksumVerificationMode is NoVerification.

This comment should be on the table.VerifyChecksum method.

levels.go, line 1008 at r10 (raw file):

		for _, t := range tables {
			errChkVerify := t.VerifyChecksum()
			if err := t.DecrRef(); err != nil {

Shouldn't we check errChkVerify before this line? What if t.VerifyChecksum returns an error and t.DecrRef() also returns an error?

options/options.go, line 39 at r10 (raw file):

	NoVerification ChecksumVerificationMode = iota
	// OnTableRead indicates checksum should be verified while opening SSTtable.
	OnTableRead

Why is this called OnTableRead and not OnTableOpen? The comment says checksum should be verified while opening SSTable

table/builder.go, line 188 at r10 (raw file):

	y.AssertTrue((len(b.entryOffsets)+1)*4+4+8+4 < math.MaxUint32) // check for below statements
	// We should include current entry also in size, thats why +1 to len(b.entryOffsets).

nit: that's why

table/table_test.go, line 648 at r10 (raw file):

	f.WriteAt(rb, rand.Int63n(fi.Size()))

	_, err = OpenTable(f, options.LoadToRAM, options.OnTableAndBlockRead)

The table should be closed.

Reviewable status: 12 of 14 files reviewed, 9 unresolved discussions (waiting on @golangcibot, @jarifibrahim, and @manishrjain)

db.go, line 463 at r10 (raw file):

I think it should be here. This tells even if opt.ChecksumVerificatinMode is NoVerification, then also this function can be called to verify checksum.

levels.go, line 1008 at r10 (raw file):

If both of them returns error, I am just logging error from t.DecrRef(). In any case, we should decrease table reference first.

options/options.go, line 39 at r10 (raw file):

Table read here means, reading table from disk, which is table open.

table/builder.go, line 188 at r10 (raw file):

Done.

table/table_test.go, line 648 at r10 (raw file):

Here table creation should fail, hence I am not checking for error.

Reviewed 2 of 2 files at r11.
Reviewable status: all files reviewed, 7 unresolved discussions (waiting on @ashish-goswami, @golangcibot, and @manishrjain)

db_test.go, line 1831 at r11 (raw file):

func TestVerifyChecksum(t *testing.T) {
	// user stream write for writing.

user => use

levels.go, line 1009 at r11 (raw file):

			errChkVerify := t.VerifyChecksum()
			if err := t.DecrRef(); err != nil {
				s.kv.opt.Errorf("unable to descrease reference of table: %s while "+

descrease => decrease.

Reviewable status: 12 of 14 files reviewed, 7 unresolved discussions (waiting on @golangcibot, @jarifibrahim, and @manishrjain)

db_test.go, line 1831 at r11 (raw file):

Done.

levels.go, line 1009 at r11 (raw file):

Done.