update audit, connection pool

Author: rachel-msft

articles/postgresql/concepts-audit.md

@@ -5,7 +5,7 @@ author: rachel-msft
 ms.author: raagyema
 ms.service: postgresql
 ms.topic: conceptual
-ms.date: 10/14/2019
+ms.date: 01/28/2020
 ---
 
 # Audit logging in Azure Database for PostgreSQL - Single Server
@@ -60,10 +60,8 @@ pgAudit allows you to configure session or object audit logging. [Session audit
 Once you have [installed pgAudit](#installing-pgaudit), you can configure its parameters to start logging. The [pgAudit documentation](https://github.com/pgaudit/pgaudit/blob/master/README.md#settings) provides the definition of each parameter. Test the parameters first and confirm that you are getting the expected behavior.
 
 > [!NOTE]
-> Setting `pgaudit.log_client` to ON will redirect logs to a client process (like psql) instead of being written to file. This setting should generally be left disabled.
-
-> [!NOTE]
-> `pgaudit.log_level` is only enabled when `pgaudit.log_client` is on. Also, in the Azure portal, there is currently a bug with `pgaudit.log_level`: a combo box is shown, implying that multiple levels can be selected. However, only one level should be selected. 
+> Setting `pgaudit.log_client` to ON will redirect logs to a client process (like psql) instead of being written to file. This setting should generally be left disabled. <br> <br>
+> `pgaudit.log_level` is only enabled when `pgaudit.log_client` is on.
 
 > [!NOTE]
 > In Azure Database for PostgreSQL, `pgaudit.log` cannot be set using a `-` (minus) sign shortcut as described in the pgAudit documentation. All required statement classes (READ, WRITE etc) should be individually specified.
@@ -82,6 +80,22 @@ To learn more about `log_line_prefix`, visit the [PostgreSQL documentation](http
 ### Getting started
 To quickly get started, set `pgaudit.log` to `WRITE`, and open your logs to review the output. 
 
+### Viewing audit logs
+If you are using .log files, your audit logs will be included in the same file as your PostgreSQL error logs. You can download log files from the Azure [portal](howto-configure-server-logs-in-portal.md) or [CLI](howto-configure-server-logs-using-cli.md). 
+
+If you are using Azure diagnostic logging, the way you access the logs depends on which endpoint you choose. For Azure Storage, see the [logs storage account](../azure-monitor/platform/resource-logs-collect-storage.md) article. For Event Hubs, see the [stream Azure logs](../azure-monitor/platform/resource-logs-stream-event-hubs.md) article.
+
+For Azure Monitor Logs, logs are sent to the workspace you selected. The Postgres logs use the **AzureDiagnostics** collection mode, so they can be queried from the AzureDiagnostics table. The fields in the table are described below. Learn more about querying and alerting in the [Azure Monitor Logs query](../azure-monitor/log-query/log-query-overview.md) overview.
+
+You can use this query to get started. You can configure alerts based on queries.
+
+Search for all Postgres logs for a particular server in the last day
+```
+AzureDiagnostics
+| where LogicalServerName_s == "myservername"
+| where TimeGenerated > ago(1d) 
+| where Message contains "AUDIT:"
+```
 
 ## Next steps
 - [Learn about logging in Azure Database for PostgreSQL](concepts-server-logs.md)

articles/postgresql/concepts-limits.md

@@ -5,15 +5,15 @@ author: rachel-msft
 ms.author: raagyema
 ms.service: postgresql
 ms.topic: conceptual
-ms.date: 06/25/2019
+ms.date: 01/28/2020
 ms.custom: fasttrack-edit
 ---
 # Limits in Azure Database for PostgreSQL - Single Server
 The following sections describe capacity and functional limits in the database service. If you'd like to learn about resource (compute, memory, storage) tiers, see the [pricing tiers](concepts-pricing-tiers.md) article.
 
 
 ## Maximum connections
-The maximum number of connections per pricing tier and vCores are as follows: 
+The maximum number of connections per pricing tier and vCores are shown below. The Azure system requires five connections to monitor the Azure Database for PostgreSQL server. 
 
 |**Pricing Tier**| **vCore(s)**| **Max Connections** | **Max User Connections** |
 |---|---|---|---|
@@ -34,7 +34,10 @@ The maximum number of connections per pricing tier and vCores are as follows:
 When connections exceed the limit, you may receive the following error:
 > FATAL:  sorry, too many clients already
 
-The Azure system requires five connections to monitor the Azure Database for PostgreSQL server. 
+> [!IMPORTANT]
+> For best experience, we recommend that you use a connection pooler like pgBouncer to efficiently manage connections.
+
+A PostgreSQL connection, even idle, can occupy about 10MB of memory. Also, creating new connections takes time. Most applications request many short-lived connections, which compounds this situation. The result is fewer resources available for your actual workload leading to decreased performance. A connection pooler that avoids idle connections and reuses existing connections will help address this. To learn more, visit our [blog post](https://techcommunity.microsoft.com/t5/azure-database-for-postgresql/not-all-postgres-connection-pooling-is-equal/ba-p/825717).
 
 ## Functional limitations
 ### Scale operations

articles/postgresql/concepts-server-logs.md

@@ -64,7 +64,7 @@ To enable Diagnostic logs using Powershell, CLI, or REST API, visit the [diagnos
 
 ### Access diagnostic logs
 
-The way you access the logs depends on which endpoint you choose. For Azure Storage, the schema is described in the [logs storage account](../azure-monitor/platform/resource-logs-collect-storage.md) article. For Event Hubs, see the [stream Azure logs](../azure-monitor/platform/resource-logs-stream-event-hubs.md) article.
+The way you access the logs depends on which endpoint you choose. For Azure Storage, see the [logs storage account](../azure-monitor/platform/resource-logs-collect-storage.md) article. For Event Hubs, see the [stream Azure logs](../azure-monitor/platform/resource-logs-stream-event-hubs.md) article.
 
 For Azure Monitor Logs, logs are sent to the workspace you selected. The Postgres logs use the **AzureDiagnostics** collection mode, so they can be queried from the AzureDiagnostics table. The fields in the table are described below. Learn more about querying and alerting in the [Azure Monitor Logs query](../azure-monitor/log-query/log-query-overview.md) overview.
 
@@ -73,7 +73,7 @@ The following are queries you can try to get started. You can configure alerts b
 Search for all Postgres logs for a particular server in the last day
 ```
 AzureDiagnostics
-| where LogicalServerName_s == 'myservername'
+| where LogicalServerName_s == "myservername"
 | where TimeGenerated > ago(1d) 
 ```