I've been researching moving from Storage Account table storage to CosmosDB table storage. Currently I am using the WindowsAzure.Storage (9.3.3) library to query data in a .net core 3.1 application. As part of this migration I have switched to the Microsoft.Azure.Cosmos.Table 1.0.7 library. I wrote the LinqPad benchmark below to compare the performance of both when doing a full table scan.
async Task Main()
{
var timer = Stopwatch.StartNew();
await QueryCosmosDb().ConfigureAwait(false);
timer.Stop();
var cosmosExecutionTime = timer.Elapsed;
timer = Stopwatch.StartNew();
await QueryTableStorage().ConfigureAwait(false);
timer.Stop();
var tableExecutionTime = timer.Elapsed;
cosmosExecutionTime.Dump();
tableExecutionTime.Dump();
}
public async Task QueryCosmosDb()
{
var cosmosTableEndpoint = new Uri($"https://***.table.cosmos.azure.com:443/");
var storageAccount = new Microsoft.Azure.Cosmos.Table.CloudStorageAccount(new Microsoft.Azure.Cosmos.Table.StorageCredentials("***", "****"), cosmosTableEndpoint);
var client = storageAccount.CreateCloudTableClient();
var table = client.GetTableReference("tablename");
var query = new Microsoft.Azure.Cosmos.Table.TableQuery();
Microsoft.Azure.Cosmos.Table.TableContinuationToken token = null;
do
{
var segment = await table.ExecuteQuerySegmentedAsync(query, token).ConfigureAwait(false);
token = segment.ContinuationToken.Dump();
}
while (token != null);
}
public async Task QueryTableStorage()
{
var storageAccount = new Microsoft.WindowsAzure.Storage.CloudStorageAccount(new Microsoft.WindowsAzure.Storage.Auth.StorageCredentials("***", "****"), true);
var client = storageAccount.CreateCloudTableClient();
var table = client.GetTableReference("tablename");
var query = new Microsoft.WindowsAzure.Storage.Table.TableQuery();
Microsoft.WindowsAzure.Storage.Table.TableContinuationToken token = null;
do
{
var segment = await table.ExecuteQuerySegmentedAsync(query, token).ConfigureAwait(false);
token = segment.ContinuationToken;
}
while (token != null);
}
The Storage Account table and CosmosDb table have an identical datasets of roughly 200k entities.
The Cosmos Table Account has a shared provision throughput of 2200 RUs.
When using the Cosmos Executor with the Microsoft.Azure.Cosmos.Table library I am getting an execution time of ~3 hours. The Storage Account table with the Microsoft.WindowsAzure.Storage library takes ~2 minutes. If I switch the Microsoft.Azure.Cosmos.Table library to use the rest executor in the Cloud Table Client I get an execution time of ~3 minutes.
Has anyone encountered similar behavior or aware of issues around empty table queries?
Also added ticket to Github Issues in azure-cosmos-table-dotnet
