btr0cur.c: (f08cf9cf) · Commits · Software / OSDI20 Artifacts / mariadb

innobase/btr/btr0cur.c

+65 −2

Original line number	Diff line number	Diff line
		@@ -85,6 +85,15 @@ btr_rec_free_updated_extern_fields(
		inherited fields */
		mtr_t* mtr); /* in: mini-transaction handle which contains
		an X-latch to record page and to the tree */
		/***************************************************************
		Gets the externally stored size of a record, in units of a database page. */
		static
		ulint
		btr_rec_get_externally_stored_len(
		/==============================/
		/* out: externally stored part, in units of a
		database page */
		rec_t* rec); /* in: record */

		/==================== B-TREE SEARCH =========================/

		@@ -2540,6 +2549,7 @@ btr_estimate_number_of_different_key_vals(
		ulint matched_bytes;
		ulint* n_diff;
		ulint not_empty_flag = 0;
		ulint total_external_size = 0;
		ulint i;
		ulint j;
		mtr_t mtr;
		@@ -2587,9 +2597,14 @@ btr_estimate_number_of_different_key_vals(
		n_diff[j]++;
		}

		total_external_size +=
		btr_rec_get_externally_stored_len(rec);

		rec = page_rec_get_next(rec);
		}

		total_external_size +=
		btr_rec_get_externally_stored_len(rec);
		mtr_commit(&mtr);
		}

		@@ -2597,12 +2612,18 @@ btr_estimate_number_of_different_key_vals(
		BTR_KEY_VAL_ESTIMATE_N_PAGES leaf pages, we can estimate how many
		there will be in index->stat_n_leaf_pages */

		/* We must take into account that our sample actually represents
		also the pages used for external storage of fields (those pages are
		included in index->stat_n_leaf_pages) */

		for (j = 0; j <= n_cols; j++) {
		index->stat_n_diff_key_vals[j] =
		(n_diff[j] * index->stat_n_leaf_pages
		+ BTR_KEY_VAL_ESTIMATE_N_PAGES - 1
		+ total_external_size
		+ not_empty_flag)
		/ BTR_KEY_VAL_ESTIMATE_N_PAGES;
		/ (BTR_KEY_VAL_ESTIMATE_N_PAGES
		+ total_external_size);
		}

		mem_free(n_diff);
		@@ -2610,6 +2631,48 @@ btr_estimate_number_of_different_key_vals(

		/================== EXTERNAL STORAGE OF BIG FIELDS ===================/

		/***************************************************************
		Gets the externally stored size of a record, in units of a database page. */
		static
		ulint
		btr_rec_get_externally_stored_len(
		/==============================/
		/* out: externally stored part, in units of a
		database page */
		rec_t* rec) /* in: record */
		{
		ulint n_fields;
		byte* data;
		ulint local_len;
		ulint extern_len;
		ulint total_extern_len = 0;
		ulint i;

		if (rec_get_data_size(rec) <= REC_1BYTE_OFFS_LIMIT) {

		return(0);
		}

		n_fields = rec_get_n_fields(rec);

		for (i = 0; i < n_fields; i++) {
		if (rec_get_nth_field_extern_bit(rec, i)) {

		data = rec_get_nth_field(rec, i, &local_len);

		local_len -= BTR_EXTERN_FIELD_REF_SIZE;

		extern_len = mach_read_from_4(data + local_len
		+ BTR_EXTERN_LEN + 4);

		total_extern_len += ut_calc_align(extern_len,
		UNIV_PAGE_SIZE);
		}
		}

		return(total_extern_len / UNIV_PAGE_SIZE);
		}

		/***********************************************************************
		Sets the ownership bit of an externally stored field in a record. */
		static