Add config flag for deleting old data

Keeping it is very useful for testing.

connector-mango/example-config.toml

@@ -24,3 +24,4 @@ retry_query_sleep_secs = 5
 retry_connection_sleep_secs = 30
 fatal_connection_timeout_secs = 600
 allow_invalid_certs = false
+delete_old_data = true

connector-raw/example-config.toml

@@ -24,3 +24,4 @@ retry_query_sleep_secs = 5
 retry_connection_sleep_secs = 30
 fatal_connection_timeout_secs = 600
 allow_invalid_certs = false
+delete_old_data = true

lib/src/lib.rs

@@ -82,6 +82,8 @@ pub struct PostgresConfig {
     pub fatal_connection_timeout_secs: u64,
     /// Allow invalid TLS certificates, passed to native_tls danger_accept_invalid_certs
     pub allow_invalid_certs: bool,
+    /// Delete old data automatically, keeping only the current data snapshot
+    pub delete_old_data: bool,
 }
 
 #[derive(Clone, Debug, Deserialize)]

lib/src/postgres_target.rs

@@ -170,7 +170,10 @@ struct SlotsProcessing {
 }
 
 impl SlotsProcessing {
-    fn new(tables: &Vec<String>) -> Self {
+    fn new(tables: &Vec<String>, delete_old_data: bool) -> Self {
+        let cleanup_table_sql = Vec::<String>::new();
+
+        if delete_old_data {
             // Delete:
             // 1. account writes that came before the newest rooted write
             // 2. account writes that came after the newest rooted write but before
@@ -211,7 +214,9 @@ impl SlotsProcessing {
                 .collect();
 
             // Delete old slots
-        cleanup_table_sql.push("DELETE FROM slot WHERE slot + 100000 < $newest_final_slot".into());
+            cleanup_table_sql
+                .push("DELETE FROM slot WHERE slot + 100000 < $newest_final_slot".into());
+        }
 
         Self { cleanup_table_sql }
     }
@@ -264,7 +269,7 @@ impl SlotsProcessing {
                 .context("updating preceding non-rooted slots")?;
 
             // Keep only the newest rooted account write and also
-            // wipe old slots
+            // wipe old slots (if configured)
             for cleanup_sql in &self.cleanup_table_sql {
                 let query = query_dyn!(cleanup_sql, newest_final_slot = update.slot)?;
                 let _ = query
@@ -407,7 +412,7 @@ pub async fn init(
         .iter()
         .map(|table| table.table_name().to_string())
         .collect();
-    let slots_processing = SlotsProcessing::new(&table_names);
+    let slots_processing = SlotsProcessing::new(&table_names, config.delete_old_data);
     for _ in 0..config.slot_update_connection_count {
         let postgres_slot =
             postgres_connection(config, metric_con_retries.clone(), metric_con_live.clone())