From 92488e1f18086412a5e9c43f006a421ed86dd797 Mon Sep 17 00:00:00 2001
From: Michael Wunderlich <mwunderl@amazon.com>
Date: Tue, 14 Apr 2026 16:35:00 +0000
Subject: [PATCH 1/3] Add database tutorials (batch 10)

---
 tuts/153-dynamodb-streams/dynamodb-streams.sh | 22 ++++++++++++++++
 .../dynamodb-global-tables.sh                 | 21 ++++++++++++++++
 tuts/164-rds-snapshots/rds-snapshots.sh       | 13 ++++++++++
 tuts/168-dynamodb-queries/dynamodb-queries.sh | 23 +++++++++++++++++
 tuts/173-dynamodb-ttl/dynamodb-ttl.sh         | 25 +++++++++++++++++++
 5 files changed, 104 insertions(+)
 create mode 100644 tuts/153-dynamodb-streams/dynamodb-streams.sh
 create mode 100644 tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh
 create mode 100644 tuts/164-rds-snapshots/rds-snapshots.sh
 create mode 100644 tuts/168-dynamodb-queries/dynamodb-queries.sh
 create mode 100644 tuts/173-dynamodb-ttl/dynamodb-ttl.sh

diff --git a/tuts/153-dynamodb-streams/dynamodb-streams.sh b/tuts/153-dynamodb-streams/dynamodb-streams.sh
new file mode 100644
index 00000000..bdcf7376
--- /dev/null
+++ b/tuts/153-dynamodb-streams/dynamodb-streams.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-streams.log") 2>&1
+REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-stream-${RANDOM_ID}"
+handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
+cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
+echo "Step 1: Creating table with streams enabled"
+aws dynamodb create-table --table-name "$TABLE" --key-schema AttributeName=pk,KeyType=HASH --attribute-definitions AttributeName=pk,AttributeType=S --billing-mode PAY_PER_REQUEST --stream-specification StreamEnabled=true,StreamViewType=NEW_AND_OLD_IMAGES --query 'TableDescription.{Table:TableName,Stream:LatestStreamArn}' --output table
+aws dynamodb wait table-exists --table-name "$TABLE"
+STREAM_ARN=$(aws dynamodb describe-table --table-name "$TABLE" --query 'Table.LatestStreamArn' --output text)
+echo "Step 2: Writing items to trigger stream events"
+aws dynamodb put-item --table-name "$TABLE" --item '{"pk":{"S":"user-1"},"name":{"S":"Alice"},"age":{"N":"30"}}' 2>/dev/null
+aws dynamodb put-item --table-name "$TABLE" --item '{"pk":{"S":"user-2"},"name":{"S":"Bob"},"age":{"N":"25"}}' 2>/dev/null
+aws dynamodb update-item --table-name "$TABLE" --key '{"pk":{"S":"user-1"}}' --update-expression "SET age = :a" --expression-attribute-values '{":a":{"N":"31"}}' 2>/dev/null
+aws dynamodb delete-item --table-name "$TABLE" --key '{"pk":{"S":"user-2"}}' 2>/dev/null
+echo "  4 operations: 2 puts, 1 update, 1 delete"
+echo "Step 3: Reading stream records"
+SHARD_ID=$(aws dynamodbstreams describe-stream --stream-arn "$STREAM_ARN" --query 'StreamDescription.Shards[0].ShardId' --output text)
+ITERATOR=$(aws dynamodbstreams get-shard-iterator --stream-arn "$STREAM_ARN" --shard-id "$SHARD_ID" --shard-iterator-type TRIM_HORIZON --query 'ShardIterator' --output text)
+aws dynamodbstreams get-records --shard-iterator "$ITERATOR" --query 'Records[].{Event:eventName,Keys:dynamodb.Keys}' --output table
+echo ""; echo "Tutorial complete."
+echo "Do you want to clean up? (y/n): "; read -r CHOICE; [[ "$CHOICE" =~ ^[Yy]$ ]] && cleanup
diff --git a/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh b/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh
new file mode 100644
index 00000000..d9cac7b7
--- /dev/null
+++ b/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-global.log") 2>&1
+REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-global-${RANDOM_ID}"
+handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
+cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
+echo "Step 1: Creating table"
+aws dynamodb create-table --table-name "$TABLE" --key-schema AttributeName=pk,KeyType=HASH --attribute-definitions AttributeName=pk,AttributeType=S --billing-mode PAY_PER_REQUEST --query 'TableDescription.TableName' --output text > /dev/null
+aws dynamodb wait table-exists --table-name "$TABLE"
+echo "Step 2: Enabling point-in-time recovery"
+aws dynamodb update-continuous-backups --table-name "$TABLE" --point-in-time-recovery-specification PointInTimeRecoveryEnabled=true > /dev/null
+echo "  PITR enabled"
+echo "Step 3: Describing continuous backups"
+aws dynamodb describe-continuous-backups --table-name "$TABLE" --query 'ContinuousBackupsDescription.{Status:ContinuousBackupsStatus,PITR:PointInTimeRecoveryDescription.PointInTimeRecoveryStatus}' --output table
+echo "Step 4: Writing and reading items"
+aws dynamodb put-item --table-name "$TABLE" --item '{"pk":{"S":"item-1"},"data":{"S":"Hello"}}' 2>/dev/null
+aws dynamodb get-item --table-name "$TABLE" --key '{"pk":{"S":"item-1"}}' --query 'Item.{pk:pk.S,data:data.S}' --output table
+echo "Step 5: Table details"
+aws dynamodb describe-table --table-name "$TABLE" --query 'Table.{Name:TableName,Status:TableStatus,Items:ItemCount,Billing:BillingModeSummary.BillingMode}' --output table
+echo ""; echo "Tutorial complete."
+echo "Do you want to clean up? (y/n): "; read -r CHOICE; [[ "$CHOICE" =~ ^[Yy]$ ]] && cleanup
diff --git a/tuts/164-rds-snapshots/rds-snapshots.sh b/tuts/164-rds-snapshots/rds-snapshots.sh
new file mode 100644
index 00000000..876f497a
--- /dev/null
+++ b/tuts/164-rds-snapshots/rds-snapshots.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/rds-snap.log") 2>&1
+REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+echo "Step 1: Listing RDS instances"
+aws rds describe-db-instances --query 'DBInstances[:5].{Id:DBInstanceIdentifier,Engine:Engine,Status:DBInstanceStatus,Class:DBInstanceClass}' --output table 2>/dev/null || echo "  No RDS instances"
+echo "Step 2: Listing automated snapshots"
+aws rds describe-db-snapshots --snapshot-type automated --query 'DBSnapshots[:5].{Id:DBSnapshotIdentifier,Instance:DBInstanceIdentifier,Status:Status,Engine:Engine}' --output table 2>/dev/null || echo "  No automated snapshots"
+echo "Step 3: Listing manual snapshots"
+aws rds describe-db-snapshots --snapshot-type manual --query 'DBSnapshots[:5].{Id:DBSnapshotIdentifier,Status:Status,Size:AllocatedStorage}' --output table 2>/dev/null || echo "  No manual snapshots"
+echo "Step 4: Listing cluster snapshots"
+aws rds describe-db-cluster-snapshots --query 'DBClusterSnapshots[:3].{Id:DBClusterSnapshotIdentifier,Cluster:DBClusterIdentifier,Status:Status}' --output table 2>/dev/null || echo "  No cluster snapshots"
+echo ""; echo "Tutorial complete. No resources created — read-only."
+rm -rf "$WORK_DIR"
diff --git a/tuts/168-dynamodb-queries/dynamodb-queries.sh b/tuts/168-dynamodb-queries/dynamodb-queries.sh
new file mode 100644
index 00000000..eafb4744
--- /dev/null
+++ b/tuts/168-dynamodb-queries/dynamodb-queries.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-query.log") 2>&1
+REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-query-${RANDOM_ID}"
+handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
+cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
+echo "Step 1: Creating table with GSI"
+aws dynamodb create-table --table-name "$TABLE" --key-schema AttributeName=pk,KeyType=HASH AttributeName=sk,KeyType=RANGE --attribute-definitions AttributeName=pk,AttributeType=S AttributeName=sk,AttributeType=S AttributeName=status,AttributeType=S --billing-mode PAY_PER_REQUEST --global-secondary-indexes '[{"IndexName":"status-index","KeySchema":[{"AttributeName":"status","KeyType":"HASH"},{"AttributeName":"sk","KeyType":"RANGE"}],"Projection":{"ProjectionType":"ALL"}}]' > /dev/null
+aws dynamodb wait table-exists --table-name "$TABLE"
+echo "Step 2: Writing items"
+for i in 1 2 3 4 5; do
+    STATUS=$( [ $((i % 2)) -eq 0 ] && echo "active" || echo "inactive" )
+    aws dynamodb put-item --table-name "$TABLE" --item "{\"pk\":{\"S\":\"user-$i\"},\"sk\":{\"S\":\"profile\"},\"name\":{\"S\":\"User $i\"},\"status\":{\"S\":\"$STATUS\"}}" 2>/dev/null
+done
+echo "  Wrote 5 items"
+echo "Step 3: Query by partition key"
+aws dynamodb query --table-name "$TABLE" --key-condition-expression "pk = :pk" --expression-attribute-values '{":pk":{"S":"user-1"}}' --query 'Items[].{pk:pk.S,name:name.S,status:status.S}' --output table
+echo "Step 4: Query GSI (active users)"
+aws dynamodb query --table-name "$TABLE" --index-name status-index --key-condition-expression "#s = :s" --expression-attribute-names '{"#s":"status"}' --expression-attribute-values '{":s":{"S":"active"}}' --query 'Items[].{pk:pk.S,name:name.S}' --output table
+echo "Step 5: Scan with filter"
+aws dynamodb scan --table-name "$TABLE" --filter-expression "#s = :s" --expression-attribute-names '{"#s":"status"}' --expression-attribute-values '{":s":{"S":"inactive"}}' --query '{Count:Count,Items:Items[].{pk:pk.S,name:name.S}}' --output table
+echo ""; echo "Tutorial complete."
+echo "Do you want to clean up? (y/n): "; read -r CHOICE; [[ "$CHOICE" =~ ^[Yy]$ ]] && cleanup
diff --git a/tuts/173-dynamodb-ttl/dynamodb-ttl.sh b/tuts/173-dynamodb-ttl/dynamodb-ttl.sh
new file mode 100644
index 00000000..d4f35f1b
--- /dev/null
+++ b/tuts/173-dynamodb-ttl/dynamodb-ttl.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ttl.log") 2>&1
+REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-ttl-${RANDOM_ID}"
+handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
+cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
+echo "Step 1: Creating table"
+aws dynamodb create-table --table-name "$TABLE" --key-schema AttributeName=pk,KeyType=HASH --attribute-definitions AttributeName=pk,AttributeType=S --billing-mode PAY_PER_REQUEST > /dev/null
+aws dynamodb wait table-exists --table-name "$TABLE"
+echo "Step 2: Enabling TTL"
+aws dynamodb update-time-to-live --table-name "$TABLE" --time-to-live-specification Enabled=true,AttributeName=expires_at > /dev/null
+echo "  TTL enabled on 'expires_at' attribute"
+echo "Step 3: Writing items with TTL"
+PAST=$(($(date +%s) - 3600))
+FUTURE=$(($(date +%s) + 86400))
+aws dynamodb put-item --table-name "$TABLE" --item "{\"pk\":{\"S\":\"expired-item\"},\"data\":{\"S\":\"This should expire\"},\"expires_at\":{\"N\":\"$PAST\"}}" 2>/dev/null
+aws dynamodb put-item --table-name "$TABLE" --item "{\"pk\":{\"S\":\"active-item\"},\"data\":{\"S\":\"This stays\"},\"expires_at\":{\"N\":\"$FUTURE\"}}" 2>/dev/null
+echo "  Wrote 2 items (1 expired, 1 active)"
+echo "Step 4: Describing TTL"
+aws dynamodb describe-time-to-live --table-name "$TABLE" --query 'TimeToLiveDescription.{Status:TimeToLiveStatus,Attribute:AttributeName}' --output table
+echo "Step 5: Scanning items"
+aws dynamodb scan --table-name "$TABLE" --query 'Items[].{pk:pk.S,data:data.S,expires:expires_at.N}' --output table
+echo "  Note: DynamoDB deletes expired items within 48 hours, not immediately"
+echo ""; echo "Tutorial complete."
+echo "Do you want to clean up? (y/n): "; read -r CHOICE; [[ "$CHOICE" =~ ^[Yy]$ ]] && cleanup

From 3a3bd5e779828f0d203578dcbd029e00de904dc4 Mon Sep 17 00:00:00 2001
From: Michael Wunderlich <mwunderl@amazon.com>
Date: Tue, 21 Apr 2026 05:17:16 +0000
Subject: [PATCH 2/3] Apply technical requirements (R1, R2, R9, R10, R13)

- R1: Add AWS_REGION to region fallback chain
- R2: Replace openssl rand with /dev/urandom
- R9: Remove Appendix/Generation details from READMEs
- R10: Remove internal references
- R13: Add REVISION-HISTORY.md
---
 tuts/153-dynamodb-streams/REVISION-HISTORY.md             | 8 ++++++++
 tuts/153-dynamodb-streams/dynamodb-streams.sh             | 4 ++--
 tuts/162-dynamodb-continuous-backups/REVISION-HISTORY.md  | 8 ++++++++
 .../dynamodb-global-tables.sh                             | 4 ++--
 tuts/164-rds-snapshots/REVISION-HISTORY.md                | 8 ++++++++
 tuts/164-rds-snapshots/rds-snapshots.sh                   | 2 +-
 tuts/168-dynamodb-queries/REVISION-HISTORY.md             | 8 ++++++++
 tuts/168-dynamodb-queries/dynamodb-queries.sh             | 4 ++--
 tuts/173-dynamodb-ttl/REVISION-HISTORY.md                 | 8 ++++++++
 tuts/173-dynamodb-ttl/dynamodb-ttl.sh                     | 4 ++--
 10 files changed, 49 insertions(+), 9 deletions(-)
 create mode 100644 tuts/153-dynamodb-streams/REVISION-HISTORY.md
 create mode 100644 tuts/162-dynamodb-continuous-backups/REVISION-HISTORY.md
 create mode 100644 tuts/164-rds-snapshots/REVISION-HISTORY.md
 create mode 100644 tuts/168-dynamodb-queries/REVISION-HISTORY.md
 create mode 100644 tuts/173-dynamodb-ttl/REVISION-HISTORY.md

diff --git a/tuts/153-dynamodb-streams/REVISION-HISTORY.md b/tuts/153-dynamodb-streams/REVISION-HISTORY.md
new file mode 100644
index 00000000..282b695f
--- /dev/null
+++ b/tuts/153-dynamodb-streams/REVISION-HISTORY.md
@@ -0,0 +1,8 @@
+# Revision History: 153-dynamodb-streams
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+
diff --git a/tuts/153-dynamodb-streams/dynamodb-streams.sh b/tuts/153-dynamodb-streams/dynamodb-streams.sh
index bdcf7376..cb69c4bb 100644
--- a/tuts/153-dynamodb-streams/dynamodb-streams.sh
+++ b/tuts/153-dynamodb-streams/dynamodb-streams.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-streams.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
-RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-stream-${RANDOM_ID}"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1); TABLE="tut-stream-${RANDOM_ID}"
 handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
 cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
 echo "Step 1: Creating table with streams enabled"
diff --git a/tuts/162-dynamodb-continuous-backups/REVISION-HISTORY.md b/tuts/162-dynamodb-continuous-backups/REVISION-HISTORY.md
new file mode 100644
index 00000000..2db13500
--- /dev/null
+++ b/tuts/162-dynamodb-continuous-backups/REVISION-HISTORY.md
@@ -0,0 +1,8 @@
+# Revision History: 162-dynamodb-continuous-backups
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+
diff --git a/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh b/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh
index d9cac7b7..d838d99f 100644
--- a/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh
+++ b/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-global.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
-RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-global-${RANDOM_ID}"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1); TABLE="tut-global-${RANDOM_ID}"
 handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
 cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
 echo "Step 1: Creating table"
diff --git a/tuts/164-rds-snapshots/REVISION-HISTORY.md b/tuts/164-rds-snapshots/REVISION-HISTORY.md
new file mode 100644
index 00000000..99d6de2c
--- /dev/null
+++ b/tuts/164-rds-snapshots/REVISION-HISTORY.md
@@ -0,0 +1,8 @@
+# Revision History: 164-rds-snapshots
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+
diff --git a/tuts/164-rds-snapshots/rds-snapshots.sh b/tuts/164-rds-snapshots/rds-snapshots.sh
index 876f497a..4be7c8a8 100644
--- a/tuts/164-rds-snapshots/rds-snapshots.sh
+++ b/tuts/164-rds-snapshots/rds-snapshots.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/rds-snap.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
 echo "Step 1: Listing RDS instances"
 aws rds describe-db-instances --query 'DBInstances[:5].{Id:DBInstanceIdentifier,Engine:Engine,Status:DBInstanceStatus,Class:DBInstanceClass}' --output table 2>/dev/null || echo "  No RDS instances"
 echo "Step 2: Listing automated snapshots"
diff --git a/tuts/168-dynamodb-queries/REVISION-HISTORY.md b/tuts/168-dynamodb-queries/REVISION-HISTORY.md
new file mode 100644
index 00000000..35eac78b
--- /dev/null
+++ b/tuts/168-dynamodb-queries/REVISION-HISTORY.md
@@ -0,0 +1,8 @@
+# Revision History: 168-dynamodb-queries
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+
diff --git a/tuts/168-dynamodb-queries/dynamodb-queries.sh b/tuts/168-dynamodb-queries/dynamodb-queries.sh
index eafb4744..ac08ff3c 100644
--- a/tuts/168-dynamodb-queries/dynamodb-queries.sh
+++ b/tuts/168-dynamodb-queries/dynamodb-queries.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ddb-query.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
-RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-query-${RANDOM_ID}"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1); TABLE="tut-query-${RANDOM_ID}"
 handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
 cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
 echo "Step 1: Creating table with GSI"
diff --git a/tuts/173-dynamodb-ttl/REVISION-HISTORY.md b/tuts/173-dynamodb-ttl/REVISION-HISTORY.md
new file mode 100644
index 00000000..03502a9b
--- /dev/null
+++ b/tuts/173-dynamodb-ttl/REVISION-HISTORY.md
@@ -0,0 +1,8 @@
+# Revision History: 173-dynamodb-ttl
+
+## Shell (CLI script)
+
+### 2026-04-14 v1 published
+- Type: functional
+- Initial version
+
diff --git a/tuts/173-dynamodb-ttl/dynamodb-ttl.sh b/tuts/173-dynamodb-ttl/dynamodb-ttl.sh
index d4f35f1b..841f074f 100644
--- a/tuts/173-dynamodb-ttl/dynamodb-ttl.sh
+++ b/tuts/173-dynamodb-ttl/dynamodb-ttl.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 WORK_DIR=$(mktemp -d); exec > >(tee -a "$WORK_DIR/ttl.log") 2>&1
-REGION=${AWS_DEFAULT_REGION:-$(aws configure get region 2>/dev/null)}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
-RANDOM_ID=$(openssl rand -hex 4); TABLE="tut-ttl-${RANDOM_ID}"
+REGION=${AWS_DEFAULT_REGION:-${AWS_REGION:-$(aws configure get region 2>/dev/null))}; [ -z "$REGION" ] && echo "ERROR: No region" && exit 1; export AWS_DEFAULT_REGION="$REGION"; echo "Region: $REGION"
+RANDOM_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1); TABLE="tut-ttl-${RANDOM_ID}"
 handle_error() { echo "ERROR on line $1"; trap - ERR; cleanup; exit 1; }; trap 'handle_error $LINENO' ERR
 cleanup() { echo ""; echo "Cleaning up..."; aws dynamodb delete-table --table-name "$TABLE" > /dev/null 2>&1 && echo "  Deleted table"; rm -rf "$WORK_DIR"; echo "Done."; }
 echo "Step 1: Creating table"

From 96c3be6f294c076ec58dbc5d92ad8ad8bdc05c71 Mon Sep 17 00:00:00 2001
From: Michael Wunderlich <mwunderl@amazon.com>
Date: Tue, 21 Apr 2026 05:38:00 +0000
Subject: [PATCH 3/3] Add README.md and tutorial walkthrough for script-only
 tutorials

---
 tuts/153-dynamodb-streams/README.md           | 38 ++++++++++++++++++
 tuts/153-dynamodb-streams/dynamodb-streams.md | 23 +++++++++++
 .../162-dynamodb-continuous-backups/README.md | 39 +++++++++++++++++++
 .../dynamodb-global-tables.md                 | 31 +++++++++++++++
 tuts/164-rds-snapshots/README.md              | 29 ++++++++++++++
 tuts/164-rds-snapshots/rds-snapshots.md       | 23 +++++++++++
 tuts/168-dynamodb-queries/README.md           | 39 +++++++++++++++++++
 tuts/168-dynamodb-queries/dynamodb-queries.md | 31 +++++++++++++++
 tuts/173-dynamodb-ttl/README.md               | 39 +++++++++++++++++++
 tuts/173-dynamodb-ttl/dynamodb-ttl.md         | 31 +++++++++++++++
 10 files changed, 323 insertions(+)
 create mode 100644 tuts/153-dynamodb-streams/README.md
 create mode 100644 tuts/153-dynamodb-streams/dynamodb-streams.md
 create mode 100644 tuts/162-dynamodb-continuous-backups/README.md
 create mode 100644 tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.md
 create mode 100644 tuts/164-rds-snapshots/README.md
 create mode 100644 tuts/164-rds-snapshots/rds-snapshots.md
 create mode 100644 tuts/168-dynamodb-queries/README.md
 create mode 100644 tuts/168-dynamodb-queries/dynamodb-queries.md
 create mode 100644 tuts/173-dynamodb-ttl/README.md
 create mode 100644 tuts/173-dynamodb-ttl/dynamodb-ttl.md

diff --git a/tuts/153-dynamodb-streams/README.md b/tuts/153-dynamodb-streams/README.md
new file mode 100644
index 00000000..9e460e06
--- /dev/null
+++ b/tuts/153-dynamodb-streams/README.md
@@ -0,0 +1,38 @@
+# Dynamodb Streams
+
+An AWS CLI tutorial that demonstrates Dynamodb operations.
+
+## Running
+
+```bash
+bash dynamodb-streams.sh
+```
+
+To auto-run with cleanup:
+
+```bash
+echo 'y' | bash dynamodb-streams.sh
+```
+
+## What it does
+
+1. Creating table with streams enabled
+2. Writing items to trigger stream events
+3. Reading stream records
+
+## Resources created
+
+- Table
+- Item
+
+The script prompts you to clean up resources when it finishes.
+
+## Cost
+
+Free tier eligible for most operations. Clean up resources after use to avoid charges.
+
+## Related docs
+
+- [AWS CLI dynamodb reference](https://docs.aws.amazon.com/cli/latest/reference/dynamodb/index.html)
+- [AWS CLI dynamodbstreams reference](https://docs.aws.amazon.com/cli/latest/reference/dynamodbstreams/index.html)
+
diff --git a/tuts/153-dynamodb-streams/dynamodb-streams.md b/tuts/153-dynamodb-streams/dynamodb-streams.md
new file mode 100644
index 00000000..d581480b
--- /dev/null
+++ b/tuts/153-dynamodb-streams/dynamodb-streams.md
@@ -0,0 +1,23 @@
+# Dynamodb Streams
+
+## Prerequisites
+
+1. AWS CLI installed and configured (`aws configure`)
+2. Appropriate IAM permissions for the AWS services used
+
+## Step 1: Creating table with streams enabled
+
+The script handles this step automatically. See `dynamodb-streams.sh` for the exact CLI commands.
+
+## Step 2: Writing items to trigger stream events
+
+The script handles this step automatically. See `dynamodb-streams.sh` for the exact CLI commands.
+
+## Step 3: Reading stream records
+
+The script handles this step automatically. See `dynamodb-streams.sh` for the exact CLI commands.
+
+## Cleanup
+
+The script prompts you to clean up all created resources. If you need to clean up manually, check the script log for the resource names that were created.
+
diff --git a/tuts/162-dynamodb-continuous-backups/README.md b/tuts/162-dynamodb-continuous-backups/README.md
new file mode 100644
index 00000000..9bcc5ef4
--- /dev/null
+++ b/tuts/162-dynamodb-continuous-backups/README.md
@@ -0,0 +1,39 @@
+# Dynamodb Global Tables
+
+An AWS CLI tutorial that demonstrates Dynamodb operations.
+
+## Running
+
+```bash
+bash dynamodb-global-tables.sh
+```
+
+To auto-run with cleanup:
+
+```bash
+echo 'y' | bash dynamodb-global-tables.sh
+```
+
+## What it does
+
+1. Creating table
+2. Enabling point-in-time recovery
+3. Describing continuous backups
+4. Writing and reading items
+5. Table details
+
+## Resources created
+
+- Table
+- Item
+
+The script prompts you to clean up resources when it finishes.
+
+## Cost
+
+Free tier eligible for most operations. Clean up resources after use to avoid charges.
+
+## Related docs
+
+- [AWS CLI dynamodb reference](https://docs.aws.amazon.com/cli/latest/reference/dynamodb/index.html)
+
diff --git a/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.md b/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.md
new file mode 100644
index 00000000..10c7fa6a
--- /dev/null
+++ b/tuts/162-dynamodb-continuous-backups/dynamodb-global-tables.md
@@ -0,0 +1,31 @@
+# Dynamodb Global Tables
+
+## Prerequisites
+
+1. AWS CLI installed and configured (`aws configure`)
+2. Appropriate IAM permissions for the AWS services used
+
+## Step 1: Creating table
+
+The script handles this step automatically. See `dynamodb-global-tables.sh` for the exact CLI commands.
+
+## Step 2: Enabling point-in-time recovery
+
+The script handles this step automatically. See `dynamodb-global-tables.sh` for the exact CLI commands.
+
+## Step 3: Describing continuous backups
+
+The script handles this step automatically. See `dynamodb-global-tables.sh` for the exact CLI commands.
+
+## Step 4: Writing and reading items
+
+The script handles this step automatically. See `dynamodb-global-tables.sh` for the exact CLI commands.
+
+## Step 5: Table details
+
+The script handles this step automatically. See `dynamodb-global-tables.sh` for the exact CLI commands.
+
+## Cleanup
+
+The script prompts you to clean up all created resources. If you need to clean up manually, check the script log for the resource names that were created.
+
diff --git a/tuts/164-rds-snapshots/README.md b/tuts/164-rds-snapshots/README.md
new file mode 100644
index 00000000..330a5233
--- /dev/null
+++ b/tuts/164-rds-snapshots/README.md
@@ -0,0 +1,29 @@
+# Rds Snapshots
+
+A read-only script that queries Rds resources and displays information.
+
+## Running
+
+```bash
+bash rds-snapshots.sh
+```
+
+## What it does
+
+1. Listing RDS instances
+2. Listing automated snapshots
+3. Listing manual snapshots
+4. Listing cluster snapshots
+
+## Resources created
+
+None — this script is read-only.
+
+## Cost
+
+No cost. This script only reads existing resources.
+
+## Related docs
+
+- [AWS CLI rds reference](https://docs.aws.amazon.com/cli/latest/reference/rds/index.html)
+
diff --git a/tuts/164-rds-snapshots/rds-snapshots.md b/tuts/164-rds-snapshots/rds-snapshots.md
new file mode 100644
index 00000000..380a74ce
--- /dev/null
+++ b/tuts/164-rds-snapshots/rds-snapshots.md
@@ -0,0 +1,23 @@
+# Rds Snapshots
+
+## Prerequisites
+
+1. AWS CLI installed and configured (`aws configure`)
+2. Appropriate IAM permissions for the AWS services used
+
+## Step 1: Listing RDS instances
+
+The script handles this step automatically. See `rds-snapshots.sh` for the exact CLI commands.
+
+## Step 2: Listing automated snapshots
+
+The script handles this step automatically. See `rds-snapshots.sh` for the exact CLI commands.
+
+## Step 3: Listing manual snapshots
+
+The script handles this step automatically. See `rds-snapshots.sh` for the exact CLI commands.
+
+## Step 4: Listing cluster snapshots
+
+The script handles this step automatically. See `rds-snapshots.sh` for the exact CLI commands.
+
diff --git a/tuts/168-dynamodb-queries/README.md b/tuts/168-dynamodb-queries/README.md
new file mode 100644
index 00000000..2187c237
--- /dev/null
+++ b/tuts/168-dynamodb-queries/README.md
@@ -0,0 +1,39 @@
+# Dynamodb Queries
+
+An AWS CLI tutorial that demonstrates Dynamodb operations.
+
+## Running
+
+```bash
+bash dynamodb-queries.sh
+```
+
+To auto-run with cleanup:
+
+```bash
+echo 'y' | bash dynamodb-queries.sh
+```
+
+## What it does
+
+1. Creating table with GSI
+2. Writing items
+3. Query by partition key
+4. Query GSI (active users)
+5. Scan with filter
+
+## Resources created
+
+- Table
+- Item
+
+The script prompts you to clean up resources when it finishes.
+
+## Cost
+
+Free tier eligible for most operations. Clean up resources after use to avoid charges.
+
+## Related docs
+
+- [AWS CLI dynamodb reference](https://docs.aws.amazon.com/cli/latest/reference/dynamodb/index.html)
+
diff --git a/tuts/168-dynamodb-queries/dynamodb-queries.md b/tuts/168-dynamodb-queries/dynamodb-queries.md
new file mode 100644
index 00000000..69b02921
--- /dev/null
+++ b/tuts/168-dynamodb-queries/dynamodb-queries.md
@@ -0,0 +1,31 @@
+# Dynamodb Queries
+
+## Prerequisites
+
+1. AWS CLI installed and configured (`aws configure`)
+2. Appropriate IAM permissions for the AWS services used
+
+## Step 1: Creating table with GSI
+
+The script handles this step automatically. See `dynamodb-queries.sh` for the exact CLI commands.
+
+## Step 2: Writing items
+
+The script handles this step automatically. See `dynamodb-queries.sh` for the exact CLI commands.
+
+## Step 3: Query by partition key
+
+The script handles this step automatically. See `dynamodb-queries.sh` for the exact CLI commands.
+
+## Step 4: Query GSI (active users)
+
+The script handles this step automatically. See `dynamodb-queries.sh` for the exact CLI commands.
+
+## Step 5: Scan with filter
+
+The script handles this step automatically. See `dynamodb-queries.sh` for the exact CLI commands.
+
+## Cleanup
+
+The script prompts you to clean up all created resources. If you need to clean up manually, check the script log for the resource names that were created.
+
diff --git a/tuts/173-dynamodb-ttl/README.md b/tuts/173-dynamodb-ttl/README.md
new file mode 100644
index 00000000..8e3cb7b2
--- /dev/null
+++ b/tuts/173-dynamodb-ttl/README.md
@@ -0,0 +1,39 @@
+# Dynamodb Ttl
+
+An AWS CLI tutorial that demonstrates Dynamodb operations.
+
+## Running
+
+```bash
+bash dynamodb-ttl.sh
+```
+
+To auto-run with cleanup:
+
+```bash
+echo 'y' | bash dynamodb-ttl.sh
+```
+
+## What it does
+
+1. Creating table
+2. Enabling TTL
+3. Writing items with TTL
+4. Describing TTL
+5. Scanning items
+
+## Resources created
+
+- Table
+- Item
+
+The script prompts you to clean up resources when it finishes.
+
+## Cost
+
+Free tier eligible for most operations. Clean up resources after use to avoid charges.
+
+## Related docs
+
+- [AWS CLI dynamodb reference](https://docs.aws.amazon.com/cli/latest/reference/dynamodb/index.html)
+
diff --git a/tuts/173-dynamodb-ttl/dynamodb-ttl.md b/tuts/173-dynamodb-ttl/dynamodb-ttl.md
new file mode 100644
index 00000000..7f88332c
--- /dev/null
+++ b/tuts/173-dynamodb-ttl/dynamodb-ttl.md
@@ -0,0 +1,31 @@
+# Dynamodb Ttl
+
+## Prerequisites
+
+1. AWS CLI installed and configured (`aws configure`)
+2. Appropriate IAM permissions for the AWS services used
+
+## Step 1: Creating table
+
+The script handles this step automatically. See `dynamodb-ttl.sh` for the exact CLI commands.
+
+## Step 2: Enabling TTL
+
+The script handles this step automatically. See `dynamodb-ttl.sh` for the exact CLI commands.
+
+## Step 3: Writing items with TTL
+
+The script handles this step automatically. See `dynamodb-ttl.sh` for the exact CLI commands.
+
+## Step 4: Describing TTL
+
+The script handles this step automatically. See `dynamodb-ttl.sh` for the exact CLI commands.
+
+## Step 5: Scanning items
+
+The script handles this step automatically. See `dynamodb-ttl.sh` for the exact CLI commands.
+
+## Cleanup
+
+The script prompts you to clean up all created resources. If you need to clean up manually, check the script log for the resource names that were created.
+