Fixed-length Attributes

Writing fixed-length attribute cells to an array involves populating a single buffer and serializing all values in that buffer according to the layout you are writing into (see Writing Dense Subarrays and Writing Sparse Cells). The same holds even if you defined the attribute to store any fixed number of values (>1) per cell. This is illustrated in the code block below with a sparse write, but it is applicable to dense writes as well.

#include <tiledb/tiledb.h>

// Create TileDB context
tiledb_ctx_t* ctx;
tiledb_ctx_alloc(NULL, &ctx);

// Open array for writing
tiledb_array_t* array;
tiledb_array_alloc(ctx, array_name, &array);
tiledb_array_open(ctx, array, TILEDB_WRITE);

// Prepare some data for the array
long long d1[] = {1, 2, 3, 4};
unsigned long long d1_size = sizeof(d1);
long long d2[] = {2, 1, 3, 4};
unsigned long long d2_size = sizeof(d2);
float a[] = {1.1f, 1.2f, 2.1f, 2.2f, 3.1f, 3.2f, 4.1f, 4.2f};
unsigned long long a_size = sizeof(a);

// Create the query
tiledb_query_t* query;
tiledb_query_alloc(ctx, array, TILEDB_WRITE, &query);
tiledb_query_set_layout(ctx, query, TILEDB_UNORDERED);
tiledb_query_set_data_buffer(ctx, query, "d1", d1, &d1_size);
tiledb_query_set_data_buffer(ctx, query, "d2", d2, &d2_size);
tiledb_query_set_data_buffer(ctx, query, "a", a, &a_size);

// Submit query
tiledb_query_submit(ctx, query);

// Close array
tiledb_array_close(ctx, array);

// Clean up

The code snippet above produces the following sparse fragment.

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